Strong synergy between gold nanoparticles and cobalt porphyrin induces highly efficient photocatalytic hydrogen evolution

Regulating Charge Separation Via Periodic Array Nanostructures for Plasmon-Enhanced Water Oxidation

Plasmonic resonance intensity in metallic nanostructures plays a crucial role in charge generation and separation, directly affecting plasmon-induced photocatalytic activity. Engineering strategies to enhance plasmonic effects involve designing specific nanostructures, such as triangular nanoplates with sharp corners or dimer nanostructures with hot spots. However, these approaches often lead to a trade-off between enhanced plasmonic intensity and resonance energy, which ultimately determines local charge density and photocatalytic performance. Here, inspired by theoretical predications, it is shown that a flexibly controlled plasmonic photocatalyst, consisting of an ordered array of Au nanoparticles on a SrTiO3 surface, exhibits an enhanced surface plasmon resonance (SPR) intensity while maintaining a constant SPR resonant energy, due to the presence of surface lattice resonance. This trade-off results in improved charge separation efficiency and an increase in local charge density at catalytically active sites, as verified by theoretical simulations, surface photovoltage microscopy, and ultrafast transient absorption spectroscopy. Moreover, the optimized periodic photocatalyst shows a 7-fold increase in water oxidation activity over disordered nanostructures. This work provides a novel approach for balancing the intensity and energy of SPR, which will contribute to optimizing photocatalytic activity on plasmonic platforms.

Enhanced solar hydrogen production via reconfigured semi-polar facet/cocatalyst heterointerfaces in GaN/Si photocathodes

The development of an efficient and durable photoelectrode is critical for achieving large-scale applications in photoelectrochemical water splitting. Here, we report a unique photoelectrode composed of reconfigured gallium nitride nanowire-on-silicon wafer loaded with Au nanoparticles as cocatalyst that achieved an impressive applied bias photon-to-current efficiency of 10.36% under AM 1.5G one sun illumination while exhibiting stable PEC hydrogen evolution over 800 h at a high current density. Specifically, by tailoring the GaN nanowires via a simple alkaline-etching step to expose the inner (101 ¯ 1 ¯ ) facets, we achieve a highly coupled semiconductor nanowire-cocatalyst heterointerface with strong electron interaction. The strongly coupled reconfigured GaN nanowire/Au heterointerface not only optimizes the electronic structure of Au nanoparticles to form abundant highly active interfacial regions, eventually realizing superior hydrogen evolution activity but also enables GaN nanowires to provide a stronger anchoring effect for Au nanoparticles, preventing the detachment of Au nanoparticles during the intense hydrogen evolution process. The proposed photoelectrode offers a feasible structure for overcoming the efficiency-reliability bottleneck of PEC devices for producing clean hydrogen fuel.

A Regiospecific Co-Assembly Method to Functionalize Ordered Mesoporous Metal Oxides with Customizable Noble Metal Nanocrystals

An efficient regiospecific co-assembly (RSCA) strategy is developed for general synthesis of mesoporous metal oxides with pore walls precisely decorated by highly dispersed noble metal nanocrystals with customized parameters (diameter and composition). It features the rational utilization of the specific interactions between hydrophilic molecular precursors, hydrophobic noble metal nanocrystals, and amphiphilic block copolymers, to achieve regiospecific co-assembly as confirmed by molecular dynamics simulations. Through this RSCA strategy, we achieved a controllable synthesis of a variety of functional mesoporous metal oxide composites (e.g., WO3, ZrO2, TiO2) with in-pore walls precisely decorated by various noble metal nanocrystals of tailored components (Au, Ag, Pt, Pd and their nanoalloys) and sizes (3.0-8.5 nm). As an example, the obtained mesoporous 0.5-Ag/WO3 material has a highly interconnected mesoporous structure and uniform 6.5 nm Ag nanocrystals confined in the mesopores, showing superior NO sensing performances with high sensitivity, good selectivity, and stability at low working temperature (127 °C). In situ spectroscopy study indicates that the NO sensing process involves a unique gas-solid reaction, where NO molecules are converted into chemisorbed NO x species over the sensitive materials, inducing a remarkable change of resistance and outputting a dramatic response signal.

Porphyrin-Confined Supported Ultrasmall Ir Clusters as Oxygen Evolution Catalysts for Water Electrolysis

Metalloporphyrin ligands themselves can participate in the redox process, making them beneficial in promoting the multielectron catalytic process of the oxygen evolution reaction (OER). However, OER catalysts synthesized by traditional chemical strategies face challenges in water electrolysis. We synthesized high-performance and stable alkaline and acidic OER electrocatalysts loaded with ultrasmall iridium clusters by taking advantage of the attraction and confinement of Ir atoms by the Ir-N bonds formed by the porphyrin cavity. The N in the porphyrin cavity forms an Ir-N bond with Ir so that Ir carries a negative charge and attracts Ir atoms to form ultrasmall Ir clusters above the cavity to adjust the electronic structure of the Ir clusters. The resulting catalyst Tpyp-Ir(IrOX) exhibits a small overpotential (242 and 259 mV) at a current density of 10 mA cm-2 in alkaline and acidic conditions and demonstrates good long-term operational stability. In addition, Tpyp-Ir(IrOX) exhibits a higher transition frequency (TOF) (1.69 O2 s-1 at 300 mV) in 1 M KOH, which is 7 times that of Ir/C.

Noble Metal Plasmon-Molecular Catalyst Hybrids for Renewable Energy Relevant Small Molecule Activation

Significant endeavors have been dedicated to the advancement of materials for artificial photosynthesis, aimed at efficiently harvesting light and catalyzing reactions such as hydrogen production and CO2 conversion. The application of plasmonic nanomaterials emerges as a promising option for this purpose, owing to their excellent light absorption properties and ability to confine solar energy at the nanoscale. In this regard, coupling plasmonic particles with molecular catalysts offers a pathway to create high-performance hybrid catalysts. In this review, we discuss the plasmonic-molecular complex hybrid catalysts where the plasmonic nanoparticles serve as the light-harvesting unit and promote interfacial charge transfer in tandem with the molecular catalyst which drives chemical transformation. In the initial section, we provide a concise overview of plasmonic nanomaterials and their photophysical properties. We then explore recent breakthroughs, highlighting examples from literature reports involving plasmonic-molecular complex hybrids in various catalytic processes. The utilization of plasmonic materials in conjunction with molecular catalysts represents a relatively unexplored area with substantial potential yet to be realized. This review sets a strong basis and motivation to explore the plasmon-induced hot-electron mediated photelectrochemical small molecule activation reactions. Utilizing in situ spectroscopic investigations and ultrafast transient absorption spectroscopy, it presents a comprehensive template for scalable and sustainable antenna-reactor systems.

Synergistic Coordination and Surface Plasmon Resonance of Quantum Dots in Enhancing Photocatalytic Hydrogen Evolution

Recent studies have revealed that the integration of metal nanoparticles (NPs) with photocatalysts allows the metal NPs to serve as cocatalysts, significantly enhancing reactant efficiency near nanostructures through the surface plasmon resonance (SPR) effect. On this basis, we synthesized highly reactive FePt quantum dots (FePt QDs) with tailored configurations, manipulating the Pt coordination environment and combining FePt QDs with ultrathin two-dimensional nickel metal-organic layer (Ni-MOL) nanosheets. X-ray absorption fine spectroscopy (XAFS) confirmed the distinctive Pt-Fe configuration after photoactivation. The optimized loading amount of FePt QDs led to a hydrogen evolution reaction (HER) yield of 113 mmol·g-1·h-1 after activation, with the catalyst remaining stable over five cycles. The improved reaction efficiency stemmed from Pt coordination adjustments and a localized SPR effect, supported by ultraviolet-visible (UV-vis), infrared (IR), Raman, and XAFS characterizations. A comparative analysis was conducted with Ni-MOL deposited with platinum NPs, further underscoring the distinct advantages of FePt QDs and corroborating by density functional theory (DFT) calculations, which revealed favorable d-band center properties. These findings offer a promising avenue for the development of highly efficient and stable nanoalloy photocatalysts.

The paradox of thermal vs. non-thermal effects in plasmonic photocatalysis

The debate surrounding the roles of thermal and non-thermal pathways in plasmonic catalysis has captured the attention of researchers and sparked vibrant discussions within the scientific community. In this review, we embark on a thorough exploration of this intriguing discourse, starting from fundamental principles and culminating in a detailed understanding of the divergent viewpoints. We probe into the core of the debate by elucidating the behavior of excited charge carriers in illuminated plasmonic nanostructures, which serves as the foundation for the two opposing schools of thought. We present the key arguments and evidence put forth by proponents of both the non-thermal and thermal pathways, providing a perspective on their respective positions. Beyond the theoretical divide, we discussed the evolving methodologies used to unravel these mechanisms. We discuss the use of Arrhenius equations and their variations, shedding light on the ensuing debates about their applicability. Our review emphasizes the significance of localized surface plasmon resonance (LSPR), investigating its role in collective charge oscillations and the decay dynamics that influence catalytic processes. We also talked about the nuances of activation energy, exploring its relationship with the nonlinearity of temperature and light intensity dependence on reaction rates. Additionally, we address the intricacies of catalyst surface temperature measurements and their implications in understanding light-triggered reaction dynamics. The review further discusses wavelength-dependent reaction rates, kinetic isotope effects, and competitive electron transfer reactions, offering an all-inclusive view of the field. This review not only maps the current landscape of plasmonic photocatalysis but also facilitates future explorations and innovations to unlock the full potential of plasmon-mediated catalysis, where synergistic approaches could lead to different vistas in chemical transformations.

Co-Assembly of Polyoxometalates and Porphyrins as Anode for High-Performance Lithium-Ion Batteries

Polyoxometalates (POMs) have been considered one of the most promising anode candidates for lithium-ion batteries (LIBs) in virtue of their high theoretical capacity and reversible multielectron redox properties. However, the poor intrinsic electronic conductivity, low specific surface area, and high solubility in organic electrolytes hinder their widespread applications in LIBs. Herein, a novel hybrid nanomaterial is synthesized by co-assembling POMs and porphyrins (PMo12/CoTPyP) through a facile solvothermal method. The POM clusters are stabilized by porphyrin units through electrostatic interactions, which simultaneously realize the uniform dispersion of POMs and porphyrin units. Benefiting from the generated sub-1 nm channels for fast ion transport and the synergistic effect between evenly distributed PMo12 clusters and high-conductive CoTPyP units, the LIB based on the optimized PMo12/CoTPyP anode exhibits significantly improved Li+ storage capability as well as superior rate and cycling performance. The results of density functional theory simulations further reveal that the co-assembly of PMo12 and CoTPyP can accelerate the mobility of Li+ and electrons, which in turn promotes the enhancement of LIBs performance. This work paves a strategy for synthesizing POMs-based anode materials with simultaneously high dispersibility, redox activity, and stability.

Efficient Charge Separation in Ag/PCN/UPDI Ternary Heterojunction for Optimized Photothermal-Photocatalytic Performance via Tandem Electric Fields

Charge separation driven by the internal electric field is a research hotspot in photocatalysis. However, it remains challenging to accurately control the electric field to continuously accelerate the charge transfer. Herein, a strategy of constructing a tandem electric field to continuously accelerate charge transfer in photocatalysts is proposed. The plasma electric field, interface electric field, and intramolecular electric field are integrated into the Ag/g-C3N4/urea perylene imide (Ag/PCN/UPDI) ternary heterojunction to achieve faster charge separation and longer carrier lifetime. The triple electric fields function as three accelerators on the charge transport path, promoting the separation of electron-hole pairs, accelerating charge transfer, enhancing light absorption, and increasing the concentration of energetic electrons on the catalyst. The H2 evolution rate of Ag/PCN/UPDI is 16.8 times higher than that of pristine PDI, while the degradation rate of oxytetracycline is increased by 4.5 times. This new strategy will provide a groundbreaking idea for the development of high-efficiency photocatalysts.

Rational design of covalent organic frameworks/NaTaO3 S-scheme heterostructure for enhanced photocatalytic hydrogen evolution

As a typical perovskite material, NaTaO3 has been regarded as a potential catalyst for photocatalytic hydrogen evolution (PHE) process, due to its excellent photoelectric property and superior chemical stability. However, the photocatalytic activity of pure NaTaO3 was largely restricted by its poor visible-light absorption ability and rapid recombination of photogenerated charge carriers. Therefore, a covalently bonded TpBpy covalent organic framework (COF)/NaTaO3 (TpBpy/NaTaO3) heterostructure was designed and synthesized by the post modification strategy with (3-aminopropyl) triethoxysilane (APTES) and the in situ solvothermal process. Benefiting from the enhanced built-in electric field by the interfacial covalent bonds and the formation of S-scheme heterostructure between TpBpy and NaTaO3, which were proved by the Ar+-cluster depth profile and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculation results, both the charge transfer efficiency and the PHE performance of the TpBpy/NaTaO3 composites were significantly improved. Additionally, the composites exhibited an excellent absorption performance in the visible region, which was also beneficial for the photocatalytic process. As expected, the optimal TpBpy/20%NaTaO3 composite achieved a remarkable hydrogen evolution rate of 17.3 mmol·g-1·h-1 (10 mg of catalyst) under simulated sunlight irradiation, which was about 173 and 2.4 times higher than that of pure NaTaO3 and TpBpy, respectively. This work provided a novel strategy for constructing highly effective and stable semiconductor/COFs heterostructures with strong interfacial interaction for photocatalytic hydrogen evolution.

Raman Monitoring of the Electro-Optical Synergy-Induced Enhancements in Carbon-Bromine Bond Cleavage, Reaction Rate, and Product Selectivity of p-Bromothiophenol

Electro-optical synergy has recently been targeted to improve the separation of hot carriers and thereby further improve the efficiency of plasmon-mediated chemical reactions (PMCRs). However, the electro-optical synergy in PMCRs needs to be more deeply understood, and its contribution to bond dissociation and product selectivity needs to be clarified. Herein, the electro-optical synergy in plasmon-mediated reduction of p-bromothiophenol (PBTP) was studied on a plasmonic nanostructured silver electrode using in situ Raman spectroscopy and theoretical calculations. It was found that the electro-optical synergy-induced enhancements in the cleavage of carbon-bromine bonds, reaction rate, and product selectivity (4,4'-biphenyl dithiol vs thiophenol) were largely affected by the applied bias, laser wavelength, and laser power. The theoretical simulation further clarified that the strong electro-optical synergy is attributed to the matching of energy band diagrams of the plasmonic silver with those of the adsorbed PBTP molecules. A deep understanding of the electro-optical synergy in PBTP reduction and the clarification of the mechanism will be highly beneficial for the development of other highly efficient PMCRs.

In Situ Photodeposition of Gold Nanoparticles with Exposed High-Activity Crystal Facets under Different Sacrificial Agents

In situ photodeposition presents a powerful approach for integrating noble metal co-catalysts onto semiconductor surfaces. However, achieving precise control over the microstructure of the deposited co-catalyst remains a major challenge. Au nanoparticles (NPs) are deposited onto H-KCNO using HAuCl4 in the presence of various sacrificial agents in this study. Notably, the choice of sacrificial agent decisively influences the exposed crystal facets, loaded content, and particle size of the deposited Au NPs. Importantly, in situ photodeposition under an ethanol solution facilitates the exposure of the highly active (111) and (220) crystal facets of Au. The introduction of Au NPs significantly enhances photocatalytic hydrogen evolution, achieving rates of 4.93, 57.88, and 15.44 μmol/h for H-KCNO/Au-(water, ethanol, and lactic acid), respectively. The observed photocatalytic activity for hydrogen evolution indicates that the exposure of the highly active planes emerges as critical for significant performance enhancement. Photoelectrochemical and photoluminescence measurements suggest that the highly active (111) and (220) crystal facets effectively segregate sites for redox reactions, thereby impeding the recombination of photogenerated electron-hole pairs.

Hymenaea courbaril resin-mediated gold nanoparticles as catalysts in organic dyes degradation and sensors in pharmaceutical pollutants

In this study, green synthesis of gold nanoparticles (AuNPs) using aqueous extract from Hymenaea courbaril resin (HCR) is reported. The successful formation, functional group involvement, size, and morphology of the subject H. courbaril resin mediated gold nanoparticles (HCRAuNPs) were confirmed by Ultra Violet-Visible (UV-vis) spectroscopy, Fourier-Transform Infrared spectroscopy (FTIR), and Transmission Electron Microscopy (TEM) techniques. Stable and high yield of HCRAuNPs was formed in 1:15 (aqueous solution: salt solution) reacted in sunlight as indicated by the visual colour change and appearance of surface Plasmon resonance (SPR) at 560 nm. From the FT-IR results, the phenolic hydroxyl (-OH) functional group was found to be involved in synthesis and stabilization of nanoparticles. The TEM analysis showed that the particles are highly dispersed and spherical in shape with average size of 17.5 nm. The synthesized HCRAuNPs showed significant degradation potential against organic dyes, including methylene blue (MB, 85 %), methyl orange (MO, 90 %), congo red (CR, 83 %), and para nitrophenol (PNP, 76 %) up to 180 min. The nanoparticles also demonstrated the effective detection of pharmaceutical pollutants, including amoxicillin, levofloxacin, and azithromycin in aqueous environment as observable changes in color and UV-Vis spectral graph.

Hot or Not? Reassessing Mechanisms of Photocurrent Generation in Plasmon-Enhanced Electrocatalysis

It is now widely accepted that certain effects arising from localised surface plasmon resonance, such as enhanced electromagnetic fields, hot carriers, and thermal effects, can facilitate electrocatalytic processes. This newly emerging field of research is commonly referred to as plasmon-enhanced electrocatalysis (PEEC) and is attracting increasing interest from the research community, particularly regarding harnessing the high energy of hot carriers. However, this has led to a lack of critical analysis in the literature, where the participation of hot carriers is routinely claimed due to their perceived desirability, while the contribution of other effects is often not sufficiently investigated. As a result, correctly differentiating between the possible mechanisms at play has become a key point of contention. In this review, we specifically focus on the mechanisms behind photocurrents observed in PEEC and critically evaluate the possibility of alternative sources of current enhancement in the reported PEEC systems. Furthermore, we present guidelines for the best experimental practices and methods to distinguish between the various enhancement mechanisms in PEEC.

Engineering a hierarchically micro-/nanostructured Si@Au-based artificial enzyme with improved accessibility of active sites for enhanced catalysis

The active site accessibility and high loading of gold nanoparticles (AuNPs) are key factors affecting the catalytic activity of supported AuNP-based catalysts. However, the preparation of supported AuNP-based catalysts with highly accessible active sites still remains a challenge. Herein, sphere-on-sphere (SoS) silica microspheres with a hierarchical structure, good dispersion and high surface density of thiol groups (10 SH nm-2) are prepared and used as a platform for the growth of high-density AuNPs. The obtained hierarchical Si@Au micro-/nanostructure consisting of 0.55 μm SoS silica microspheres and 7.3 nm AuNPs (SoS-0.55@Au-7.3) is found to show excellent peroxidase-mimicking activity (Km = 0.033 mM and Vmax = 34.6 × 10-8 M s-1) with merits of high stability and good reusability. Furthermore, the as-obtained SoS-0.55@Au-7.3-based system can sensitively detect hydrogen peroxide (H2O2) with a low detection limit of 1.6 μM and a wide linear range from 2.5 μM to 1.0 mM. The high catalytic activity, excellent stability and good reusability of SoS-0.55@Au-7.3 imply its great prospects in biosensing and biomedical analysis.

Hydrogen evolution with hot electrons on a plasmonic-molecular catalyst hybrid system

Plasmonic systems convert light into electrical charges and heat, mediating catalytic transformations. However, there is ongoing controversy regarding the involvement of hot carriers in the catalytic process. In this study, we demonstrate the direct utilisation of plasmon hot electrons in the hydrogen evolution reaction with visible light. We intentionally assemble a plasmonic nanohybrid system comprising NiO/Au/[Co(1,10-Phenanthrolin-5-amine)2(H2O)2], which is unstable at water thermolysis temperatures. This assembly limits the plasmon thermal contribution while ensuring that hot carriers are the primary contributors to the catalytic process. By combining photoelectrocatalysis with advanced in situ spectroscopies, we can substantiate a reaction mechanism in which plasmon-induced hot electrons play a crucial role. These plasmonic hot electrons are directed into phenanthroline ligands, facilitating the rapid, concerted proton-electron transfer steps essential for hydrogen generation. The catalytic response to light modulation aligns with the distinctive profile of a hot carrier-mediated process, featuring a positive, though non-essential, heat contribution.

Enhanced Photoinduced Carrier Separation in Fe-MOF-525/CdS for Photocatalytic Hydrogen Evolution: Improved Catalytic Dynamics with Specific Active Sites

Single-atom metal-anchored porphyrin-based metal-organic frameworks (MOFs) have shown excellent light absorption, catalytic sites, and high stability during photocatalytic reactions, while there are still challenges for facile assembly with quantum dots to enhance catalytic dynamics. Herein, a kind of Fe single atom-doped MOF material (Fe-MOF-525) was ball milled with CdS in a proper ratio through Fe-N4 and Fe-N-C bonding, which showed the enhanced photoinduced carrier separation ability. As a result, extended light absorption ranges of CdS/Fe-MOF-5252.3 induced the promotion of the photocatalytic hydrogen (H2) value (3638.6 μmol g-1 h-1), which was 7.2 and 2.3 times higher than those of Fe-MOF-525 and CdS. In this work, the facile synthetic technique, specific active sites, and enhanced catalytic dynamics in the composite highlight the future research on MOF-based heterojunctions and their potential photocatalysis applications..

Boosting the Plasmon-Mediated Electrochemical Oxidation of p-Aminothiophenol with p-Hydroxythiophenol as Molecular Cocatalyst

Plasmon-mediated electrochemistry is an emerging area of interest in which the electrochemical reactions are enhanced by employing metal nanostructures possessing localized surface plasmon resonance (LSPR). However, the reaction efficacy is still far below its theoretical limit due to the ultrafast relaxation of LSPR-generated hot carriers. Herein, we introduce p-hydroxythiophenol (PHTP) as a molecular cocatalyst to significantly improve the reaction efficacy in plasmon-mediated electrochemical oxidation of p-aminothiophenol (PATP) on gold nanoparticles. Using electrochemical techniques, in situ Raman spectroscopy, and theoretical calculations, we elucidate that the presence of PHTP improves the hot hole-mediated electrochemical oxidation of PATP by 2-fold through the trapping of plasmon-mediated hot electrons. In addition, the selectivity of PATP oxidation could also be modulated by the introduction of PHTP cocatalyst. This tactic of employing molecular cocatalyst can be drawn out to endorse various plasmonic electrochemical reactions because of its simple protocol, high efficiency, and high selectivity.

Selectively Adsorbed p-Aminothiophenol Molecules Improve the Electrocatalytic and Photo-Electrocatalytic Hydrogen Evolution on Au/TiO2

Electrocatalytic hydrogen evolution reaction (HER) is receiving increasing attention as an effective process to produce clean energy. The commonly used precious metal catalysts can be hybridized with semiconductors to form heterostructures for the improvement of catalytic efficiency and reduction of cost. It will be promising to further improve the efficiency of heterostructure-based nanocatalysts in electrocatalytic and photocatalytic HER using a simple and effective method. Herein, we improve the efficiency of Au/TiO2 in electrocatalytic and photo-electrocatalytic HER by selectively adsorbing p-aminothiophenol (PATP) molecules. The PATP molecules are adsorbed on the gold surface by using a simple solution-based method and favor the charge separation at the Au-TiO2 interface. We also compare the PATP molecules with other thiophenol molecules in the enhancement of electrocatalytic HER. The PATP-induced enhancement in electrocatalysis is then further investigated by density functional theory (DFT) calculations, and this enhancement is attributed to a reduction in Gibbs energy of adsorbed hydrogen after surface adsorption of PATP molecules. This work provides a simple, cost-effective, and highly efficient approach to improve the electrocatalytic and photo-electrocatalytic efficiency of Au/TiO2, and this approach could be easily extended to other heterostructure-based nanocatalysts for performance enhancement and may be used in many other catalytic reactions.

Chitosan-Derived Nitrogen-Doped Carbon as a Support of Cobalt(II)-Phthalocyanine/Gold Nanoparticles for Photocatalytic Water Splitting

Water splitting is considered one of the worthy approaches to generate hydrogen as a green fuel with diverse applications. Promoting this reaction with the photocatalytic strategy enjoys a free source of solar energy, without the use of expensive instruments. In this research, gold nanoparticles and cobalt(II)-phthalocyanine were deposited on nitrogen-doped carbon, obtained from chitosan, to afford a photocatalytic water splitting at the rate of 792 mol molAu-1 h-1. Gold as the catalyst in contact with cobalt(II)-phthalocyanine as the sensitizer and nitrogen-doped carbon as the support/semiconductor provided a desired heterojunction for the photocatalytic purpose. The nanocomposite showed remarkable light harvesting in the region of visible light with a band gap of 2.01 eV. While a facile protocol to the synthesis of the mentioned photocatalyst by a simple thermal treatment of cobalt(II)-phthalocyanine and chitosan could be invaluable, this research pointed out the significance of cobalt(II)-phthalocyanine as the sensitizer in the gold photocatalytic transformations.

Enhancing Photocatalytic Hydrogen Evolution by Synergistic Benefits of MXene Cocatalysis and Homo-Interface Engineering

Photocatalytic water splitting holds great promise as a sustainable and cost-effectiveness alternative for the production of hydrogen. Nevertheless, the practical implementation of this strategy is hindered by suboptimal visible light utilization and sluggish charge carrier dynamics, leading to low yield. MXene is a promising cocatalyst due to its high conductivity, abundance of active sites, tunable terminal functional groups, and great specific surface area. Homo-interface has perfect lattice matching and uniform composition, which are more conducive to photogenerated carriers' separation and migration. In this study, a novel ternary heterogeneous photocatalyst, a-TiO2 /H-TiO2 /Ti3 C2 MXene (MXTi), is presented using an electrostatic self-assembly method. Compared to commercial P25, pristine anatase, and rutile TiO2 , as-prepared MXTi exhibit exceptional photocatalytic hydrogen evolution performance, achieving a rate of 0.387 mmol h-1 . The significant improvement is attributable to the synergistic effect of homo-interface engineering and Ti3 C2 MXene, which leads to widened light absorption and efficient carrier transportation. The findings highlight the potential of interface engineering and MXene cocatalyst loading as a proactive approach to enhance the performance of photocatalytic water splitting, paving the way for more sustainable and efficient hydrogen production.

Recent Progress in Porphyrin/g-C3N4 Composite Photocatalysts for Solar Energy Utilization and Conversion

Transforming solar energy into chemical bonds is a promising and viable way to store solar energy. Porphyrins are natural light-capturing antennas, and graphitic carbon nitride (g-C₃N₄) is an effective, artificially synthesized organic semiconductor. Their excellent complementarity has led to a growing number of research papers on porphyrin/g-C₃N₄ hybrids for solar energy utilization. This review highlights the recent progress in porphyrin/g-C₃N₄ composites, including: (1) porphyrin molecules/g-C₃N₄ composite photocatalysts connected via noncovalent or covalent interactions, and (2) porphyrin-based nanomaterials/g-C₃N₄ composite photocatalysts, such as porphyrin-based MOF/g-C₃N₄, porphyrin-based COF/g-C₃N₄, and porphyrin-based assembly/g-C₃N₄ heterojunction nanostructures. Additionally, the review discusses the versatile applications of these composites, including artificial photosynthesis for hydrogen evolution, CO₂ reduction, and pollutant degradation. Lastly, critical summaries and perspectives on the challenges and future directions in this field are also provided.