Electronic Structure Design of Transition Metal-Based Catalysts for Electrochemical Carbon Dioxide Reduction

With the increasingly serious greenhouse effect, the electrochemical carbon dioxide reduction reaction (CO2RR) has garnered widespread attention as it is capable of leveraging renewable energy to convert CO2 into value-added chemicals and fuels. However, the performance of CO2RR can hardly meet expectations because of the diverse intermediates and complicated reaction processes, necessitating the exploitation of highly efficient catalysts. In recent years, with advanced characterization technologies and theoretical simulations, the exploration of catalytic mechanisms has gradually deepened into the electronic structure of catalysts and their interactions with intermediates, which serve as a bridge to facilitate the deeper comprehension of structure-performance relationships. Transition metal-based catalysts (TMCs), extensively applied in electrochemical CO2RR, demonstrate substantial potential for further electronic structure modulation, given their abundance of d electrons. Herein, we discuss the representative feasible strategies to modulate the electronic structure of catalysts, including doping, vacancy, alloying, heterostructure, strain, and phase engineering. These approaches profoundly alter the inherent properties of TMCs and their interaction with intermediates, thereby greatly affecting the reaction rate and pathway of CO2RR. It is believed that the rational electronic structure design and modulation can fundamentally provide viable directions and strategies for the development of advanced catalysts toward efficient electrochemical conversion of CO2 and many other small molecules.

China's carbon-neutral policies will reduce short-term PM2.5-associated excess incidence of cardiovascular diseases

China's carbon-neutral target could have benefits for ambient fine particulate matter (PM2.5)-associated mortality. Although previous studies have researched such benefits, the potential impact on cardiovascular disease incidence burden is yet to be investigated thoroughly. Here, we first estimate the association between short-term PM2.5 exposure and the incidence of stroke and coronary heart disease (CHD) via a case-crossover study before projecting future changes in short-term PM2.5-associated excess incidence across China from 2025 to 2060 under three different emission scenarios. We find that, compared to the 2015-2020 baseline, average PM2.5 concentrations nationwide in 2060 under SSP119 (an approximation of a carbon-neutral scenario) are projected to decrease by 81.07%. The short-term PM2.5-related excess incidence of stroke and CHD is projected to be reduced to 3,352 cases (95% confidence interval: 939, 5,738)-compared with 34,485 cases under a medium-emissions scenario (SSP245)-and is expected to be accompanied by a 95% reduction in the related economic burden. China's carbon-neutral policies are likely to bring health benefits for cardiovascular disease by reducing short-term PM2.5-related incidence burden.

Carbon Neutral Hand Surgery: Simple Changes to Reduce Carbon Footprint

Introduction: Rapid climate change poses a major challenge to healthcare. The operating room is especially responsible for carbon emission, with 20% to 70% of hospital waste traced back to the operating room. This literature review aims to suggest changes that can be made in hand surgery for a more sustainable practice. Methods: A literature search was conducted from PubMed, Medline, and other online search engines with the keywords "carbon footprint, environmental health, carbon neutral, plastic surgery, hand surgery, surgery." Results: "Reduce, Reuse, Recycle, Research, Rethink and Culture" was the framework used to recommend a more carbon neutral practice. In reduction, techniques such as cutting down oversupply of materials, adopting protocols to perform cases in ambulatory settings, and simple measures to reduce energy were identified as valuable methods. Modified sterilization techniques and reprocessing single-use devices were techniques identified for reuse and recycling involved single-stream recycling, staff training, and donation of basic surgical supplies. Research involved adopting data-driven programs for life cycle assessment of all equipment in the operating room, while the use of telemedicine and "green meetings' were suggested for rethinking. Finally, strategies to encourage a team approach to environmental responsibility were discussed. Conclusion: Carbon neutral practice must be implemented to safeguard sustainable and cost-effective operating rooms and healthcare systems. Hand surgery can pave the way for other specialties through the use of available resources to develop guidelines for carbon neutral practice. This requires active effort from hand surgeons to act as role models for other healthcare professionals.

Assessment of utilization potential of biomass volatiles and biochar as a reducing agent for iron ore pellets

ABSTRACTIndia is an agricultural country and near about 500 MT of agricultural wastes are generated each year. India has huge reserves of low-grade iron ore fines. Therefore, considering the availability of these two, the present study mainly focuses on utilization of solid waste in iron and steel industry; also, biomass being carbon-neutral fuel, promotes mitigation of environmental issues. To carry out this study, agricultural wastes like groundnut shell and corn cob which contain more than 70% of volatile matter were considered. Hence, an attempt has been taken to utilize this volatiles as well as char (prepared at 350°C) of corn cob and groundnut shell as a reducing agent for reduction of iron ore pellets. Maximum reduction percentage was achieved at 1000°C and 75 min using corn cob as a reductant, i.e. 78.38% with its volatile and 92.01% using its char. Higher intensity of elemental iron is also reflected by X-ray Diffraction analysis of reduced pellets. Further, cost estimation of reduction of iron ore pellets was also done using both the reducing agents, which signifies that the reduction process using biomass volatiles is much more economical than biochar. The total cost of producing DRI from corn cob volatiles is 56% less than coal followed by groundnut shell volatiles 53.36% and minimum in the case of groundnut shell char 36.17%.Highlights Effects of biomass volatiles and char on iron ore pellets reduction @ 1000°C at different time interval of 15, 30, 45, 60 & 75 min.Comparative assessment of iron ore pellets reduction through XRD and FESEM analysis.Economic evaluation of iron ore reduction using volatiles and char of biomass.

Emissions Reduction Strategies for the Orange and Cherry Industries in New South Wales

The orange and cherry industries in New South Wales, Australia, are major horticulture industries with a high export value. Climate change has resulted in the carbon footprint of products being used by consumers to guide purchases meaning that products with a relatively high carbon footprint risk losing market access. The carbon footprint of cherry and orange production is unknown and there is no assessment of the success of climate change mitigation strategies to reduce the carbon footprint of their production and move production towards being carbon neutral. This study assesses the climate change mitigation potential of five management changes to on-farm cherry and orange production (revegetation, the use of nitrification inhibitors, renewable energy, green N fertilisers, and pyrolysis of orchard residues) over a 25-year period. for example, orchards in relevant growing regions. The results show that the carbon footprint of production can be reduced by 73 and 83% for cherries and oranges, respectively, when strategies that avoid emissions are included in their production. When strategies that sequester C from the atmosphere are also included, cherry and orange production becomes C negative in the first few years of the scenario. The economics of implementing these strategies are unfavourable, at present; however, our results indicate that the NSW cherry and orange industries can be confident in achieving emissions reductions in on-farm production to assure market access for their products.

Perceptions and priorities of perioperative staff and the public for sustainable surgery: a validated questionnaire study

Surgery is a substantial contributor to healthcare-related emissions. Despite a drive to improve sustainability, few interventions have been adopted. Stakeholder engagement is considered a key barrier to implementation. This study aimed to determine the attitudes and beliefs of the perioperative staff and the public regarding sustainability initiatives in surgery, and whether differences exist between the two groups.

Materials and Methods

Separate validated healthcare professional and public questionnaires were developed using a stepwise process. A systematic review was undertaken using Medline, Embase and Cochrane to identify key domains pertaining to sustainability and ensure content validity. Initial questionnaires were developed and refined using an iterative process of feedback from focus groups. Psychometric validation was conducted to remove question ambiguity. The final validated questionnaire was distributed to perioperative staff and the public using a multimodal approach involving online tools and in person.

Results

Only 37.1% of perioperative staff reported the implementation of sustainability initiatives in their departments. Yet, staff (45.7%) and the public (48.2%) somewhat agreed that sustainability should influence a surgeon's procedural decision-making. Insufficient staff education regarding sustainability was a potential cause for the lack of adoption, with 71.4% reporting they had no formal training. Moreover, discrepancies in the perceived importance of sustainability may have contributed. Staff and the public agreed that outcomes (38.6 vs. 42.7%, P=0.767) and surgeon experience with a technique (28.6 vs. 40.0%, P=0.082) were more important than sustainability. However, 40.9% of the public did not consider operative time an important factor compared to sustainability, while 45.7% of staff would only tolerate procedures 25% longer.

Conclusions

Engaging stakeholders is central to implementing long-term environmentally sustainable initiatives in surgery without compromising patient outcomes. More work is needed to understand the relative trade-offs considered by perioperative staff and the public, as well as provide both groups with more pertinent education on ecological outcomes.

Resource degradation of pharmacy sludge in sub-supercritical system with high degradation rate of 99% and formic acid yield of 32.44

In response to the social goal of 'carbon peak and carbon neutral' in the 14th Five-Year Plan of China, this article used Enrofloxacin (ENR), a common antibiotic, as a model compound to study the method of efficiently degrading pharmaceutical sludge and simultaneously producing Formic Acid (FA), hydrogen storage energy, in a sub-supercritical system. The Ni/SnO2 bimetallic catalyst, which was prepared by the equal volume impregnation method, was used for the liquid phase catalysis. As shown by the results, when the reaction temperature was 330°C, and the addition amount of H2O2 was 0.38 mL, the degradation rate of antibiotics could reach 99% after the reaction proceeded for 6 h. In terms of the resource utilization, the yield of FA could reach up to 32.44%. The resource utilization efficiency with Ni/SnO2 catalyst in sub-/supercritical reaction was about 2.5 times higher than that without catalyst. The kinetic reaction model was established to explore the reaction rate of the antibiotic degradation process. In addition, the Ea and the frequency factor of the reaction were 6455 J/mol and 5.78, respectively. As shown by characterization, the prepared Ni/SnO2 bimetallic catalyst had good activity and has already passed repeated stability experiments. In short, this method has broad application prospects in antibiotic catalysis and resource degradation.

Tuning Ionic Liquid-Based Catalysts for CO2 Conversion into Quinazoline-2,4(1H,3H)-diones

Carbon capture and storage (CCS) and carbon capture and utilization (CCU) are two kinds of strategies to reduce the CO₂ concentration in the atmosphere, which is emitted from the burning of fossil fuels and leads to the greenhouse effect. With the unique properties of ionic liquids (ILs), such as low vapor pressures, tunable structures, high solubilities, and high thermal and chemical stabilities, they could be used as solvents and catalysts for CO₂ capture and conversion into value-added chemicals. In this critical review, we mainly focus our attention on the tuning IL-based catalysts for CO₂ conversion into quinazoline-2,4(1H,3H)-diones from o-aminobenzonitriles during this decade (2012~2022). Due to the importance of basicity and nucleophilicity of catalysts, kinds of ILs with basic anions such as [OH], carboxylates, aprotic heterocyclic anions, etc., for conversion CO₂ and o-aminobenzonitriles into quinazoline-2,4(1H,3H)-diones via different catalytic mechanisms, including amino preferential activation, CO₂ preferential activation, and simultaneous amino and CO₂ activation, are investigated systematically. Finally, future directions and prospects for CO₂ conversion by IL-based catalysts are outlined. This review is benefit for academic researchers to obtain an overall understanding of the synthesis of quinazoline-2,4(1H,3H)-diones from CO₂ and o-aminobenzonitriles by IL-based catalysts. This work will also open a door to develop novel IL-based catalysts for the conversion of other acid gases such as SO₂ and H₂S.

Effect of 3-nitrooxypropanol on enteric methane emissions of feedlot cattle fed with a tempered barley-based diet with canola oil

A dose-response experiment was designed to examine the effect of 3-nitrooxypropanol (3-NOP) on methane (CH4) emissions, rumen function and performance of feedlot cattle fed a tempered barley-based diet with canola oil. Twenty Angus steers of initial body weight (BW) of 356 ± 14.4 kg were allocated in a randomized complete block design. Initial BW was used as the blocking criterion. Cattle were housed in individual indoor pens for 112 d, including the first 21 d of adaptation followed by a 90-d finishing period when five different 3-NOP inclusion rates were compared: 0 mg/kg dry matter (DM; control), 50 mg/kg DM, 75 mg/kg DM, 100 mg/kg DM, and 125 mg/kg DM. Daily CH4 production was measured on day 7 (last day of starter diet), day 14 (last day of the first intermediate diet), and day 21 (last day of the second intermediate diet) of the adaptation period and on days 28, 49, 70, 91, and 112 of the finisher period using open circuit respiration chambers. Rumen digesta samples were collected from each steer on the day prior to chamber measurement postfeeding, and prefeeding on the day after the chamber measurement, for determination of rumen volatile fatty acids (VFA), ammonium-N, protozoa enumeration, pH, and reduction potential. Dry matter intake (DMI) was recorded daily and BW weekly. Data were analyzed in a mixed model including period, 3-NOP dose and their interaction as fixed effects, and block as a random effect. Our results demonstrated both a linear and quadratic (decreasing rate of change) effect on CH4 production (g/d) and CH4 yield (g/kg DMI) as 3-NOP dose increased (P < 0.01). The achieved mitigation for CH4 yield in our study ranged from approximately 65.5% up to 87.6% relative to control steers fed a finishing feedlot diet. Our results revealed that 3-NOP dose did not alter rumen fermentation parameters such as ammonium-N, VFA concentration nor VFA molar proportions. Although this experimental design was not focused on the effect of 3-NOP dose on feedlot performance, no negative effects of any 3-NOP dose were detected on animal production parameters. Ultimately, the knowledge on the CH4 suppression pattern of 3-NOP may facilitate sustainable pathways for the feedlot industry to lower its carbon footprint.

Co-Benefits of Energy Structure Transformation and Pollution Control for Air Quality and Public Health until 2050 in Guangdong, China

In order to mitigate global warming and improve air quality, the transformation of regional energy structures is the most important development pathway. China, as a major global consumer of fossil fuels, will face great pressure in this regard. Aiming toward achieving the global 2 °C warming target in China, this study takes one of the most developed regions of China, Guangdong Province, as the research area in order to explore a future development pathway and potential air quality attainment until 2050, by developing two energy structure scenarios (BAU_Energy and 2Deg_Energy) and three end-of-pipe scenarios (NFC, CLE, and MTFR), and simulating future air quality and related health impacts for the different scenarios using the WRF-Chem model. The results show that under the energy transformation scenario, total energy consumption in Guangdong rises from 296 Mtce (million tons of coal equivalent) in 2015 to 329 Mtce in 2050, with electricity and clean energy accounting for 45% and 35%. In 2050, the transformation of the energy structure leads to 64%, 75%, and 46% reductions in the emissions of CO₂, NOx, and SO₂ compared with those in 2015. Together with the most stringent end-of-pipe control measures, the emissions of VOCs and primary PM_2.5 are effectively reduced by 66% and 78%. The annual average PM_2.5 and MDA8 (daily maximum 8 h O₃) concentrations in Guangdong are 33.8 and 85.9 μg/m³ in 2015, with 63.4 thousand premature deaths (95% CI: 57.1-70.8) due to environmental exposure. Under the baseline scenario, no improvement is gained in air quality or public health by 2050. In contrast, the PM_2.5 and MDA8 concentrations decline to 21.7 and 75.5 μg/m³ under the scenario with energy structure transformation, and total premature deaths are reduced to 35.5 thousand (31.9-39.5). When further combined with the most stringent end-of-pipe control measures, the PM_2.5 concentrations decrease to 16.5 μg/m³, but there is no significant improvement for ozone, with premature deaths declining to 20.6 thousand (18.5-23.0). This study demonstrates that the transformation of energy structure toward climate goals could be effective in mitigating air pollution in Guangdong and would bring significant health benefits. Compared with the end-of-pipe control policies, transformation of the energy structure is a more effective way to improve regional air quality in the long term, and synergistic promotion of both is crucial for regional development.

Covalent Organic Frameworks with Ionic Liquid-Moieties (ILCOFs): Structures, Synthesis, and CO2 Conversion

CO₂, an acidic gas, is usually emitted from the combustion of fossil fuels and leads to the formation of acid rain and greenhouse effects. CO₂ can be used to produce kinds of value-added chemicals from a viewpoint based on carbon capture, utilization, and storage (CCUS). With the combination of unique structures and properties of ionic liquids (ILs) and covalent organic frameworks (COFs), covalent organic frameworks with ionic liquid-moieties (ILCOFs) have been developed as a kind of novel and efficient sorbent, catalyst, and electrolyte since 2016. In this critical review, we first focus on the structures and synthesis of different kinds of ILCOFs materials, including ILCOFs with IL moieties located on the main linkers, on the nodes, and on the side chains. We then discuss the ILCOFs for CO₂ capture and conversion, including the reduction and cycloaddition of CO₂. Finally, future directions and prospects for ILCOFs are outlined. This review is beneficial for academic researchers in obtaining an overall understanding of ILCOFs and their application of CO₂ conversion. This work will open a door to develop novel ILCOFs materials for the capture, separation, and utilization of other typical acid, basic, or neutral gases such as SO₂, H₂S, NOx, NH₃, and so on.

The Pathway to China's Carbon Neutrality Based on an Endogenous Technology CGE Model

Global warming resulting from greenhouse gas emissions has been a worldwide issue facing humanity. Simultaneously, governments have the challenging task of striking a judicious balance between increased economic growth and decreased carbon emissions. Based on the energy-environment-economy triple coupling (3E-CGE) model, we endogenously integrate climate-friendly technologies into the model’s analysis framework through logic curves and refine and modify the CGE model’s energy use and carbon emission modules. We conduct a scenario simulation and sensitivity analysis on carbon tax, carbon-trading, and climate-friendly technological progress, respectively. The results reveal that carbon tax and carbon trading contribute to reducing carbon emissions in the short-term but achieving the goals of peak carbon and carbon neutrality will cause the collapse of the economic system. In the long-term, climate-friendly technologies are key to achieving the dual carbon goal; the development of such technologies can also stimulate economic development. The best path for China to achieve its dual carbon goals and economic development in the next 40 years involves effectively combining the carbon tax, carbon trading, and a climate-friendly technological progress. Specifically, China can begin trading carbon in high-emissions industries then impose industry-wide carbon taxes.

[Advances in synthetic biology of CO2 fixation by heterotrophic microorganisms]

Human activities increase the concentration of atmospheric carbon dioxide (CO₂), which leads to global climate warming. Microbial CO₂ fixation is a promising green approach for carbon neutral. In contrast to autotrophic microorganisms, heterotrophic microorganisms are characterized by fast growth and ease of genetic modification, but the efficiency of CO₂ fixation is still limited. In the past decade, synthetic biology-based enhancement of heterotrophic CO₂ fixation has drawn wide attention, including the optimization of energy supply, modification of carboxylation pathway, and heterotrophic microorganisms-based indirect CO₂ fixation. This review focuses on the research progress in CO₂ fixation by heterotrophic microorganisms, which is expected to serve as a reference for peaking CO₂ emission and achieving carbon neutral by microbial CO₂ fixation.

Development and Functionalization of Visible-Light-Driven Water-Splitting Photocatalysts

With global warming and the depletion of fossil resources, our fossil fuel-dependent society is expected to shift to one that instead uses hydrogen (H₂) as a clean and renewable energy. To realize this, the photocatalytic water-splitting reaction, which produces H₂ from water and solar energy through photocatalysis, has attracted much attention. However, for practical use, the functionality of water-splitting photocatalysts must be further improved to efficiently absorb visible (Vis) light, which accounts for the majority of sunlight. Considering the mechanism of water-splitting photocatalysis, researchers in the various fields must be employed in this type of study to achieve this. However, for researchers in fields other than catalytic chemistry, ceramic (semiconductor) materials chemistry, and electrochemistry to participate in this field, new reviews that summarize previous reports on water-splitting photocatalysis seem to be needed. Therefore, in this review, we summarize recent studies on the development and functionalization of Vis-light-driven water-splitting photocatalysts. Through this summary, we aim to share current technology and future challenges with readers in the various fields and help expedite the practical application of Vis-light-driven water-splitting photocatalysts.

The Chinese Carbon-Neutral Goal: Challenges and Prospects

On 22 September 2020, within the backdrop of the COVID-19 global pandemic, China announced its climate goal for peak carbon emissions before 2030 and to reach carbon neutrality before 2060. This carbon-neutral goal is generally considered to cover all anthropogenic greenhouse gases. The planning effort is now in full swing in China, but the pathway to decarbonization is unclear. The needed transition towards non-fossil fuel energy and its impact on China and the world may be more profound than its reform and development over the past 40 years, but the challenges are enormous. Analysis of four representative scenarios shows significant differences in achieving the carbon-neutral goal, particularly the contribution of non-fossil fuel energy sources. The high target values for nuclear, wind, and bioenergy have approached their corresponding resource limitations, with solar energy being the exception, suggesting solar's critical role. We also found that the near-term policies that allow for a gradual transition, followed by more drastic changes after 2030, can eventually reach the carbon-neutral goal and lead to less of a reduction in cumulative emissions, thus inconsistent with the IPCC 1.5°C scenario. The challenges and prospects are discussed in the historical context of China's socio-economic reform, globalization, international collaboration, and development.

How Can We Make Hand Surgery Carbon Neutral?

BACKGROUND

Climate change is a major public health threat worldwide. Operating theaters are responsible for extensive waste production due to the resource-intensive nature of surgery, including hand surgery.

METHODS

An online literature search was performed to ascertain the approaches that surgeons may undertake to positively impact the environment.

RESULTS

Surgeons can make hand surgery more carbon neutral through various measures that have been categorized as pre-, intra-, and postoperative interventions. With all changes, the aims are to minimize waste and costs while optimizing patient outcomes.

CONCLUSIONS

Administrative obstacles to implementing pro-climate hospital changes may be overcome by also considering likely cost benefits with many environmentally friendly measures. New measures in hand surgery should consider patient safety, clinical efficacy, cost effectiveness, and the environmental impact.

Carbon myopia: The urgent need for integrated social, economic and environmental action in the livestock sector

Livestock have long been integral to food production systems, often not by choice but by need. While our knowledge of livestock greenhouse gas (GHG) emissions mitigation has evolved, the prevailing focus has been-somewhat myopically-on technology applications associated with mitigation. Here, we (1) examine the global distribution of livestock GHG emissions, (2) explore social, economic and environmental co-benefits and trade-offs associated with mitigation interventions and (3) critique approaches for quantifying GHG emissions. This review uncovered many insights. First, while GHG emissions from ruminant livestock are greatest in low- and middle-income countries (LMIC; globally, 66% of emissions are produced by Latin America and the Caribbean, East and southeast Asia and south Asia), the majority of mitigation strategies are designed for developed countries. This serious concern is heightened by the fact that 80% of growth in global meat production over the next decade will occur in LMIC. Second, few studies concurrently assess social, economic and environmental aspects of mitigation. Of the 54 interventions reviewed, only 16 had triple-bottom line benefit with medium-high mitigation potential. Third, while efforts designed to stimulate the adoption of strategies allowing both emissions reduction (ER) and carbon sequestration (CS) would achieve the greatest net emissions mitigation, CS measures have greater potential mitigation and co-benefits. The scientific community must shift attention away from the prevailing myopic lens on carbon, towards more holistic, systems-based, multi-metric approaches that carefully consider the raison d'être for livestock systems. Consequential life cycle assessments and systems-aligned 'socio-economic planetary boundaries' offer useful starting points that may uncover leverage points and cross-scale emergent properties. The derivation of harmonized, globally reconciled sustainability metrics requires iterative dialogue between stakeholders at all levels. Greater emphasis on the simultaneous characterization of multiple sustainability dimensions would help avoid situations where progress made in one area causes maladaptive outcomes in other areas.

[MIXed plastics biodegradation and UPcycling using microbial communities: the NSFC-EU 2019 project MIX-UP to help achieve "carbon neutrality"]

With the transformation and revolution of the global plastics recycling system, recycling and upcycling of mixed plastics waste not only reduces the carbon emissions of plastics during its life cycle, but also addresses its potential ecological and environmental hazards. This article summarizes an international cooperation project, "MIXed plastics biodegradation and UPcycling using microbial communities" (MIX-UP) which was funded by the National Natural Science Foundation of China and the European Union (NSFC-EU) in 2019. The consortium of MIX-UP consists of 14 partners from European Union and China. Focusing on the global issue of "plastics pollution", this Sino-European MIX-UP project took the mixed waste of petroleum-based plastics (PP, PE, PUR, PET and PS) and bio-based plastics (PLA and PHA) as starting materials for biotechnological conversion into value-added, sustainable biomaterials. MIX-UP has three subprojects: 1) identification of plastics biodegradation pathway and design & engineering of key degrading elements, 2) construction and functional regulation of microbial consortia/enzyme cocktails with high-efficiency for degradation of plastics mixtures, 3) strategy of design and utilization of plastics degradation products for production of high value materials. Through NSFC-EU complementary and cross-disciplinary cooperation, MIX-UP proposes the engineering of a new-to-nature biological route for upcycling, a low carbon and sustainable bio-treatment that is different from the traditional physico-chemical treatment, which will empower the recycling industry to a new dimension. The implementation of the project will not only help to promote innovation and development in the field of biotechnology in China, but also contribute to the achievement of China's carbon neutral goal.

Ag-decorated GaN for high-efficiency photoreduction of carbon dioxide into tunable syngas under visible light

Visible light-driven photoreduction of CO₂and H₂O to tunable syngas is an appealing strategy for both artificial carbon neutral and Fischer-Tropsch processes. However, the development of photocatalysts with high activity and selectivity remains challenging. For this case, we here design a hybrid catalyst, synthesized byin situdeposition of Ag crystals on GaN nanobelts, that delivers a tunable H₂/CO ratio between 0.5 and 3 under visible light irradiation (λ > 400 nm). The obtained photocatalyst delivers a maximal turnover frequency value of 3.85 h^-1and a corresponding yield rate of 2.12 mmol h^-1g^-1for CO production, while the photocatalytic activity keeps stable during five cycling tests. Additionally, syngas can be detected even atλ > 600 nm. Experiments and mechanistic studies reveal that the existence of Ag crystals not only extends the light absorption region but also promotes the charge transfer efficiency, and thereby leading to a photocatalytic improvement. Accordingly, the present work affords an opportunity for developing an efficient photo-driven system by using solar energy to alleviate CO₂emissions.