A Co₃O₄-embedded porous ZnO rhombic dodecahedron prepared using zeolitic imidazolate frameworks as precursors for CO₂ photoreduction

Synthesis and Characterization of MOF-Derived Structures: Recent Advances and Future Perspectives

Due to their facile tunability, metal-organic frameworks (MOFs) are employed as precursors and templates to construct advanced functional materials with unique and desired chemical, physical, mechanical, and morphological properties. By tuning MOF precursor composition and manipulating conversion processes, various MOF-derived materials commonly known as MOF derivatives can be constructed. The possibility of controlled and predictable properties makes MOF derivatives a preferred choice for numerous advanced technological applications. The innovative synthetic designs besides the plethora of interdisciplinary characterization approaches applicable to MOF derivatives provide the opportunity to perform a myriad of experiments to explore the performance and offer key insight to develop the next generation of advanced materials. Though there are many published works of literature describing various synthesis and characterization techniques of MOF derivatives, it is still not clear how the synthesis mechanism works and what are the best techniques to characterize these materials to probe their properties accurately. In this review, the recent development in synthesis techniques and mechanisms for a variety of MOF derivates such as MOF-derived metal oxides, porous carbon, composites/hybrids, and sulfides is summarized. Furthermore, the details of characterization techniques and fundamental working principles are summarized to probe the structural, mechanical, physiochemical, electrochemical, and electronic properties of MOF and MOF derivatives. The future trends and some remaining challenges in the synthesis and characterization of MOF derivatives are also discussed.

Metal-Organic Frameworks-Derived Nanocarbon Materials and Nanometal Oxides for Photocatalytic Applications

Harnessing low-density solar energy and converting it into high-density chemical energy through photocatalysis has emerged as a promising avenue for the production of chemicals and remediation of environmental pollution, which contributes to alleviating the overreliance on fossil fuels. In recent years, metal-organic frameworks (MOFs) have gained widespread application in the field of photocatalysis due to their photostability, tunable structures, and responsiveness in the visible light range. However, most MOFs exhibit relatively low response to light, limiting their practical applications. MOFs-derived nanomaterials not only retain the inherent advantages of pristine MOFs but also show enhanced light adsorption and responsiveness. This review categorizes and summarizes MOFs-derived nanomaterials, including nanocarbons and nanometal oxides, providing representative examples for the synthetic strategies of each category. Subsequently, the recent research progress on MOFs-derived materials in photocatalytic applications are systematically introduced, specifically in the areas of photocatalytic water splitting to H2, photocatalytic CO2 reduction, and photocatalytic water treatment. The corresponding mechanisms involved in each photocatalytic reaction are elaborated in detail. Finally, the review discusses the challenges and further directions faced by MOFs-derived nanomaterials in the field of photocatalysis, highlighting their potential role in advancing sustainable energy production and environmental remediation.

Recent advances of modification effect in Co3O4-based catalyst towards highly efficient photocatalysis

Tricobalt tetroxide (Co3O4) has been developed as a promising photocatalyst material for various applications. Several reports have been published on the self-modification of Co3O4 to achieve optimal photocatalytic performance. The pristine Co3O4 alone is inadequate for photocatalysis due to the rapid recombination process of photogenerated (PG) charge carriers. The modification of Co3O4 can be extended through the introduction of doping elements, incorporation of supporting materials, surface functionalization, metal loading, and combination with other photocatalysts. The addition of doping elements and support materials may enhance the photocatalysis process, although these modifications have a slight effect on decreasing the recombination process of PG charge carriers. On the other hand, combining Co3O4 with other semiconductors results in a different PG charge carrier mechanism, leading to a decrease in the recombination process and an increase in photocatalytic activity. Therefore, this work discusses recent modifications of Co3O4 and their effects on its photocatalytic performance. Additionally, the modification effects, such as enhanced surface area, generation of oxygen vacancies, tuning the band gap, and formation of heterojunctions, are reviewed to demonstrate the feasibility of separating PG charge carriers. Finally, the formation and mechanism of these modification effects are also reviewed based on theoretical and experimental approaches to validate their formation and the transfer process of charge carriers.

The Progress of Metal-Organic Framework for Boosting CO2 Conversion

With the rapid development of modern society, environmental problems, including excessive amounts of CO2 released in the atmosphere, are becoming more and more serious. It is necessary to develop new materials and technologies to reduce pollution. Among them, metal–organic frameworks (MOFs) have shown potential for application in the area of catalysis due to their ultra-high specific surface area, structural versatility, and designability as well as ease of modification and post-synthesis. Herein, we summarize recent research advances by use of MOFs for boosting CO2 conversion. Furthermore, challenges and possible research directions related to further exploration are also discussed.

Metal–Organic Frameworks (MOFs) and Materials Derived from MOFs as Catalysts for the Development of Green Processes

This review will be centered around the work that has been reported on the development of metal–organic frameworks (MOFs) serving as catalysts for the conversion of carbon dioxide into short-chain hydrocarbons and the generation of clean energies starting from biomass. MOFs have mainly been used as support for catalysts or to prepare catalysts derived from MOFs (as sacrifice template), obtaining interesting results in the hydrogenation or oxidation of biomass. They have presented a good performance in the hydrogenation of CO2 into light hydrocarbon fuels. The common patterns to be considered in the performance of the catalysts are the acidity of MOFs, metal nodes, surface area and the dispersion of the active sites, and these parameters will be discussed in this review.

Anisotropic MOF-on-MOF Growth of Isostructural Multilayer Metal-Organic Framework Heterostructures

Isostructural MOFs with similar crystallographic parameter are easily available for MOF-on-MOF growth and possible to form core–shell structure by isotropic growth. However, due to well-matched cell lattice, selective growth in isostructural MOF heterostructures remains a great challenge for engineering atypical MOF heterostructures. Herein, an anisotropic MOF-on-MOF growth strategy was developed to structure a range of multilayer sandwich-like ZIF-L heterostructures via stacking isostructural ZIF-L-Zn and ZIF-L-Co alternately with three-, five-, seven-, and more layer structures. Moreover, these heterostructures with highly designable feature were fantastic precursors for fabricating derivatives with tunable magnetic and catalytic properties. Such strategy explores a novel way of achieving anisotropic MOF-on-MOF growth between isostructural MOFs and opens up new horizons for regulating the properties by MOF modular assembly in versatile functional nanocomposites.

Metal-organic framework based electrode materials for lithium-ion batteries: a review

Metal-organic frameworks (MOFs) with efficient surface and structural properties have risen as a distinctive class of porous materials through the last few decades, which has enabled MOFs to gain attention in a wide range of applications like drug delivery, gas separation and storage, catalysis and sensors. Likewise, they have also emerged as efficient active materials in energy storage devices owing to their remarkable conducting properties. Metal-organic frameworks (MOFs) have garnered great interest in high-energy-density rechargeable batteries and super-capacitors. Herein the study presents their expanding diversity, structures and chemical compositions which can be tuned at the molecular level. It also aims to evaluate their inherently porous framework and how it facilitates electronic and ionic transportation through the charging and discharging cycles of lithium-ion batteries. In this review we have summarized the various synthesis paths to achieve a particular metal-organic framework. This study focuses mainly on the implementation of metal-organic frameworks as efficient anode and cathode materials for lithium-ion batteries (LIBs) with an evaluation of their influence on cyclic stability and discharge capacity. For this purpose, a brief assessment is made of recent developments in metal-organic frameworks as anode or cathode materials for lithium-ion batteries which would provide enlightenment in optimizing the reaction conditions for designing a MOF structure for the battery community and electrochemical energy storage applications.

Hierarchical Co0.85 Se-CdSe/MoSe2 /CdSe Sandwich-Like Heterostructured Cages for Efficient Photocatalytic CO2 Reduction

Fabricating efficient photocatalysts with rapid charge carrier separation and high visible light harvesting is an advisable strategy to improve CO₂ reduction performance. Herein, hierarchical Co_0.85 Se-CdSe/MoSe₂ /CdSe cages with sandwich-like heterostructure are prepared to act as efficient photocatalysts for CO₂ reduction. In this study, the structure and composition of the final products can be regulated through the cation-exchange reaction in the presence of ascorbic acid. In the Co_0.85 Se-CdSe/MoSe₂ /CdSe cages, MoSe₂ nanosheets function as a bridge to integrate Co_0.85 Se-CdSe and CdSe on both sides of the MoSe₂ nanosheet shell into a sandwich-like heterostructured catalyst system, which possesses multiple positive merits for photocatalysis, including accelerated transport and separation of photogenerated carriers, improved visible light utilization, and increased catalytic active sites. Thus, the optimized Co_0.85 Se-CdSe/MoSe₂ /CdSe cages exhibit remarkable visible-light photocatalytic performance and outstanding stability for CO₂ reduction with a high CO average yield of 15.04 µmol g^-1 h^-1 and 90.14% selectivity, which are much higher than those of other control samples including single-component catalysts and binary hybrid catalysts. This study provides a promising way for the design and fabrication of high-efficiency photocatalysts.

Boosting light-driven CO2 reduction into solar fuels: Mainstream avenues for engineering ZnO-based photocatalysts

The realization of artificial photosynthesis in the photocatalytic CO₂ transformation into valuable chemicals or solar fuels, such as CO, CH₄, HCOOH, and CH₃OH, by solar-light harvesting is a promising solution to both global-warming and energy-supply issues. Recently, zinc oxide (ZnO) has emerged as an excellent oxidative photocatalyst among non-titanium metal oxides due to its availability, outstanding semiconducting and optical properties, non-toxicity, affordability, and ease of synthesis. However, ZnO wide bandgap and inability to absorb in the visible region has demanded particular modification for its practical use as a sustainable photocatalyst. This review provides a panorama of the latest advancement on ZnO photocatalysis for CO₂ reduction with an overview of fundamental aspects. Various modification strategies such as transition metal and non-metal doping, loading of plasmonic metals, and surface vacancy engineering for tunning the properties and improving the performance of ZnO are elaborated. Composites or hetero-structuralization-based Z-scheme formation is also presented along with a detailed photocatalytic reduction mechanism. Moreover, a new novel Step-scheme (S-scheme) heterostructure modification with a charge transfer pathway mechanism is also highlighted. Finally, the key challenges and new directions in this field are proposed to provide a new vision for further improvement for ZnO-based photocatalytic CO₂ conversion.

Controllable generation of ZnO/ZnCo2O4 arising from bimetal-organic frameworks for electrochemical detection of naphthol isomers

The development of a rapid and low concentration detection method for naphthol isomers is of great significance for protecting human health and environmental safety due to their high toxicity and strong corrosivity. Here, we reported a novel hollow ZnO/ZnCo₂O₄ material derived by adjusting the molar ratio of Zn/Co of bimetal-organic frameworks (BMOFs) and its application for simultaneous detection of 1-naphthol (1-NAP) and 2-naphthol (2-NAP) by electrochemical methods. The oxidation peak currents of 1-NAP and 2-NAP on a ZnO/ZnCo₂O₄ modified carbon paste electrode (ZnO/ZnCo₂O₄/CPE) depended linearly on their concentrations in the range of 0.4-50 μM and 0.06-40 μM with detection limits of 0.13 and 0.02 μM, respectively. Their electrooxidation at the ZnO/ZnCo₂O₄/CPE was a one-electron and one-proton process. These excellent performances could be driven by the high conductivity and number of active sites as well as the unique structure of ZnO/ZnCo₂O₄. The tactic may shed light on developing new electrodes for fast and efficient electrochemical detection of naphthol isomers.

Recent advances in visible-light-driven carbon dioxide reduction by metal-organic frameworks

Metal-organic frameworks (MOFs) have emerged as promising materials and have attracted researchers due to their unique chemical and physical properties-design flexibility, tuneable pore channels, a high surface-to-volume ratio that allow their distinct application in diverse research fields-gas storage, gas separation, catalysis, adsorption, drug delivery, ion exchange, sensing, etc. The rapidly growing CO₂ in the atmosphere is a global concern due to the excessive use of fossil fuels in the current era. CO₂ is the prime cause of global warming and should be ameliorated either through adsorption or conversion into value-added products to protect the environment and mankind. Nowadays, MOFs are exploited as a photocatalyst for applications of CO₂ reduction. Since the use of semiconductors limits the use of visible light for photocatalytic reduction of CO₂, MOFs are promising options. The current review describes recent development in the application of MOFs as host, composites, and their derivatives in photocatalytic reduction of CO₂ to CO and different organic chemicals (HCOOH, CH₃OH, CH₄). Efficient charge separation and visible light absorption by incorporation of active sites for efficient photocatalysis have been discussed. The selection of material for high CO₂ uptake and potential strategies for the rational design and development of high-performance catalysts are outlined. Major challenges and future perspectives have also been discussed at the last of the review.

Core-Shell MOFs@MOFs: Diverse Designability and Enhanced Selectivity

Metal-Organic frameworks (MOFs), especially MOF-based composites, performed an irreplaceable role in the material fields. By virtue of the tailorability of MOFs, core-shell MOFs@MOFs composites with diverse designability and enhanced selectivity have inspired infinite scientific interest. This review will highlight an up-to-date overview of the designability and enhanced selectivity of core-shell MOFs@MOFs composites, covering the synthetic strategies of an epitaxial growth method, postsynthetic modification, and one-pot synthesis as well as the synergistic selective performance of the synthesized MOFs@MOFs in catalysis, adsorption and separation, and molecular recognition. Finally, the potential development trend and challenges toward core-shell MOFs@MOFs are addressed.

Electrode Materials for Supercapacitors: A Review of Recent Advances

The advanced electrochemical properties, such as high energy density, fast charge–discharge rates, excellent cyclic stability, and specific capacitance, make supercapacitor a fascinating electronic device. During recent decades, a significant amount of research has been dedicated to enhancing the electrochemical performance of the supercapacitors through the development of novel electrode materials. In addition to highlighting the charge storage mechanism of the three main categories of supercapacitors, including the electric double-layer capacitors (EDLCs), pseudocapacitors, and the hybrid supercapacitors, this review describes the insights of the recent electrode materials (including, carbon-based materials, metal oxide/hydroxide-based materials, and conducting polymer-based materials, 2D materials). The nanocomposites offer larger SSA, shorter ion/electron diffusion paths, thus improving the specific capacitance of supercapacitors (SCs). Besides, the incorporation of the redox-active small molecules and bio-derived functional groups displayed a significant effect on the electrochemical properties of electrode materials. These advanced properties provide a vast range of potential for the electrode materials to be utilized in different applications such as in wearable/portable/electronic devices such as all-solid-state supercapacitors, transparent/flexible supercapacitors, and asymmetric hybrid supercapacitors.

Bimetallic metal-organic frameworks and their derivatives

Bimetallic metal-organic frameworks (MOFs) have two different metal ions in the inorganic nodes. According to the metal distribution, the architecture of bimetallic MOFs can be classified into two main categories namely solid solution and core-shell structures. Various strategies have been developed to prepare bimetallic MOFs with controlled compositions and structures. Bimetallic MOFs show a synergistic effect and enhanced properties compared to their monometallic counterparts and have found many applications in the fields of gas adsorption, catalysis, energy storage and conversion, and luminescence sensing. Moreover, bimetallic MOFs can serve as excellent precursors/templates for the synthesis of functional nanomaterials with controlled sizes, compositions, and structures. Bimetallic MOF derivatives show exposed active sites, good stability and conductivity, enabling them to extend their applications to the catalysis of more challenging reactions and electrochemical energy storage and conversion. This review provides an overview of the significant advances in the development of bimetallic MOFs and their derivatives with special emphases on their preparation and applications.

Cu/ZnO Catalysts Derived from Bimetallic Metal-Organic Framework for Dimethyl Ether Synthesis from Syngas with Enhanced Selectivity and Stability

Direct conversion of syngas to dimethyl ether (DME) through the intermediate of methanol allows more efficient DME production in a simpler reactor design relative to the conventional indirect route. Although Cu/ZnO-based multicomponent catalysts are highly active for methanol synthesis in this process, the sintering issue of Cu during the prolonged reaction generally deteriorates their performance. In this work, Cu/ZnO catalysts in a novel octahedron structure are prepared by a two-step pyrolysis of Zn-doped Cu-BTC metal-organic framework (MOF) in N₂ and air. The catalyst CZ-350/A, hybrid of MOF-derived Cu/ZnO sample CZ-350 and γ-Al₂ O₃ for methanol dehydration, displays the best activity for DME formation (7.74% CO conversion and 70.05% DME selectivity) with the lowest deterioration rate over 40 h continuous reaction. Such performance is superior to its counterpart CZ-CP/A made via the conventional coprecipitation method. This is mainly due to the confinement of Cu nanoparticles within the octahedron matrix hindering their migration and aggregation. Besides, partial reduction of ZnO in the activated CZ-350 prompts the formation of Cu⁺ -O-Zn, further facilitating the DME production with the highest selectivity compared to literature results. The results clearly indicate that Cu and ZnO distribution in the catalyst architecture plays an important role in DME formation.

Highly efficient and stable p-LaFeO3/n-ZnO heterojunction photocatalyst for phenol degradation under visible light irradiation

A series of catalysts with p-LaFeO₃/n-ZnO heterostructure were designed and prepared by hydrothermal method. The structure, surface topographies, optical properties and interfacial interactions of these photocatalysts were analyzed by XRD, SEM, TEM, PL, Uv-vis DRS, XPS, COD, TOC etc., indicating that p-n heterojunction formed at the interface between p-LaFeO₃ and n-ZnO, which enhanced the photocatalytic activity. Among them, the 20%-p-LaFeO₃/n-ZnO composite exhibits the best activity for the phenol degradation under visible light. The superior photocatalytic activity of the heterojunction photocatalyst is mainly attributed to the formation of p-n heterojunction which leads to an efficient separation of photogenerated electron-hole pairs. Besides, the 20%-p-LaFeO₃/n-ZnO heterojunction photocatalyst shows the excellent photocatalytic stability after 4 cycles. And from the free radical capture experiment, the degradation of phenol is dominated by the oxidation reaction of hydroxyl radicals and direct hole oxidation. What's more, certain intermediates were detected by HPLC and 3D-EEMs. Therefore, a photocatalytic mechanism of the 20%-p-LaFeO₃/n-ZnO p-n heterojunction catalyst for phenol degradation under visible light irradiation was proposed.

Porous ZnO/Co3O4/N-doped carbon nanocages synthesized via pyrolysis of complex metal–organic framework (MOF) hybrids as an advanced lithium-ion battery anode

Metal oxides have a large storage capacity when employed as anode materials for lithium-ion batteries (LIBs). However, they often suffer from poor capacity retention due to their low electrical conductivity and huge volume variation during the charge–discharge process. To overcome these limitations, fabrication of metal oxides/carbon hybrids with hollow structures can be expected to further improve their electrochemical properties. Herein, ZnO-Co3O4 nanocomposites embedded in N-doped carbon (ZnO-Co3O4@N-C) nanocages with hollow dodecahedral shapes have been prepared successfully by the simple carbonizing and oxidizing of metal–organic frameworks (MOFs). Benefiting from the advantages of the structural features, i.e. the conductive N-doped carbon coating, the porous structure of the nanocages and the synergistic effects of different components, the as-prepared ZnO-Co3O4@N-C not only avoids particle aggregation and nanostructure cracking but also facilitates the transport of ions and electrons. As a result, the resultant ZnO-Co3O4@N-C shows a discharge capacity of 2373 mAh g−1 at the first cycle and exhibits a retention capacity of 1305 mAh g−1 even after 300 cycles at 0.1 A g−1. In addition, a reversible capacity of 948 mAh g−1 is obtained at a current density of 2 A g−1, which delivers an excellent high-rate cycle ability.

Carbon capture and conversion using metal–organic frameworks and MOF-based materials

This review summarizes recent advances and highlights the structure–property relationship on metal–organic framework-based materials for carbon dioxide capture and conversion.

Metal Organic Frameworks Based Materials for Heterogeneous Photocatalysis

The increase in environmental pollution due to the excessive use of fossil fuels has prompted the development of alternative and sustainable energy sources. As an abundant and sustainable energy, solar energy represents the most attractive and promising clean energy source for replacing fossil fuels. Metal organic frameworks (MOFs) are easily constructed and can be tailored towards favorable photocatalytic properties in pollution degradation, organic transformations, CO₂ reduction and water splitting. In this review, we first summarize the different roles of MOF materials in the photoredox chemical systems. Then, the typical applications of MOF materials in heterogeneous photocatalysis are discussed in detail. Finally, the challenges and opportunities in this promising field are evaluated.

Novel synthesis of MeOx (Ni, Cu, La)@Nano-Co3O4 from combination of complexation and impregnation in ultrasonic intervention for low temperature oxidation of toluene under microwave radiation

Nano-metal binary oxides were prepared by the combined method of complexation and impregnation in ultrasonic intervention for low temperature catalytic oxidation of toluene under microwave radiation. Activity differences of prepared samples were evaluated using the removal rate and the mineralization rate as assessment criteria. Results show that the sample derived from the introduction of La and intervention of ultrasonic presents the best catalytic performance, which the removal rate of 80% can be obtained at 120°C and the mineralization rate of 97% can be obtained at 210°C. Compared with the worst sample at low temperature, maximum increases of removal rate and mineralization rate using the sample of La-Co (US) are 3.47 and 11.79 times respectively. Lowest values of T₉₀ based on removal rate and mineralization rate are 140°C and 195°C, respectively. Compared with the sample that ultrasonic treatment is not applied in impregnation process, maximum increases of removal rate and mineralization rate using the sample of La-Co (US) are 17.43% and 85.19% respectively. Moreover, Diagrams of XRD, EDX and TEM indicate that metal binary oxides nano-particles are synthesized successfully. The data of SEM and XPS manifests that the sample of La-Co (US) possesses the smallest particle size distribution, the highest levels of the Co²⁺/Co³⁺ and the O_latt/O_ads. In addition, significant differences of catalytic activities are not observed after three cycles indicating that the sample possesses good stability and recycling.

Electrooxidation of Pd–Cu NP loaded porous carbon derived from a Cu-MOF

We have synthesized Pd–Cu NP loaded porous carbon through the direct carbonization of a porous Cu based MOF for efficient electrooxidation.

Boosted CO2 photoreduction to methane via Co doping in bismuth vanadate atomic layers

Boosted CO₂ photoreduction and high CH₄ selectivity on Co-doped BiVO₄.

Metal-Organic Framework-Derived Nanoporous Metal Oxides toward Supercapacitor Applications: Progress and Prospects

Transition metal oxides (TMOs) have attracted significant attention for energy storage applications such as supercapacitors due to their good electrical conductivity, high electrochemical response (by providing Faradaic reactions), low manufacturing costs, and easy processability. Despite exhibiting these attractive characteristics, the practical applications of TMOs for supercapacitors are still relatively limited. This is largely due to their continuous Faradaic reactions, which can lead to major changes or destruction of their structure as well phase changes (in some cases) during cycling, leading to the degradation in their capacitive performance over time. Hence, there is an immediate need to develop new synthesis methods, which will readily provide stable porous architectures, controlled phase, as well as useful control over dimensions (1-D, 2-D, and 3-D) of the metal oxides for improving their performance in supercapacitor applications. Since its discovery in late 1990s, metal-organic frameworks (MOFs) have influenced many fields of material science. In recent years, they have gained significant attention as precursors or templates for the derivation of porous metal oxide nanostructures and nanocomposites for next-generation supercapacitor applications. Even though these materials have widespread applications and have been widely studied in terms of their structural features and synthesis, it is still not clear how these materials will play an important role in the development of the supercapacitor field. In this review, we will summarize the recent developments in the field of MOF-derived porous metal oxide nanostructures and nanocomposites for supercapacitor applications. Furthermore, the current challenges along with the future trends and prospects in the application of these materials for supercapacitors will also be discussed.

Nanoarchitectured Design of Porous Materials and Nanocomposites from Metal-Organic Frameworks

The emergence of metal-organic frameworks (MOFs) as a new class of crystalline porous materials is attracting considerable attention in many fields such as catalysis, energy storage and conversion, sensors, and environmental remediation due to their controllable composition, structure and pore size. MOFs are versatile precursors for the preparation of various forms of nanomaterials as well as new multifunctional nanocomposites/hybrids, which exhibit superior functional properties compared to the individual components assembling the composites. This review provides an overview of recent developments achieved in the fabrication of porous MOF-derived nanostructures including carbons, metal oxides, metal chalcogenides (metal sulfides and selenides), metal carbides, metal phosphides and their composites. Finally, the challenges and future trends and prospects associated with the development of MOF-derived nanomaterials are also examined.

Synthesis of yellow mesoporous Ni-doped TiO2 with enhanced photoelectrochemical performance under visible light

Ordered mesoporous Ni-doped TiO₂ were synthesized by a multicomponent self-assembly process.

La2Sn2O7 enhanced photocatalytic CO2 reduction with H2O by deposition of Au co-catalyst

La₂Sn₂O₇ (LSO) micro/nanospheres, synthesized by a hydrothermal method, exhibited photocatalytic performance for CO₂ reduction.