Advances in photoelectroreduction of CO2 to hydrocarbons fuels: Contributions of functional materials

Progress in heterostructures for photoelectrocatalytic reduction of carbon dioxide into fuels and value-added products

Carbon capture and utilization (CCU) technology offers a sustainable option to simultaneously address both energy crisis and environmental pollution such as catalytic reduction of carbon dioxide (CO2) into value-added fuel products (e.g., C1-C3). Among diverse CCU strategies, the light-irradiated photoelectrocatalytic (PEC) approach is recognized as a cutting-edge option for efficient CO2 reduction reaction (RR) through the integration of photocatalysis and electrocatalysis within a one-stage hybridized catalytic system. Therefore, this review is meticulously structured to elucidate the potential utility of advanced composite catalysts (e.g., titanium dioxide, metal-organic frameworks, and organic/miscellaneous heterostructure materials) in PEC-CO2RR. It also examines the factors and processes governing their PEC-CO2RR activites in relation to their reduction pathways, electronic structures, charge-carrier dynamics, types of electrolytes, mass transfer, light-adsorption potential, and the viability of active sites. The fundamental principles and working mechanisms of diverse catalytic materials in PEC-CO2RR are also outlined to help establish the advanced catalytic systems based on performance assessments (e.g., in terms of CO2 conversion rate, quantum yield, and space-time yield). Overall, this review is expected to deliver the new path for the construction of the next-generation PEC-CO2RR systems that are upscalable, stable, and reusable with enhanced catalytic activity.

Multi-Layer Kesterite-Based Photocathodes for NH3 Photosynthesis from N2 Reduction Reaction

The necessity of new methods to substitute the Haber-Bosch process in the NH3 synthesis, generating fewer greenhouse gases, and dispensing less energy, drove the investigation of the photoelectrocatalytic approach in the N2 reduction reaction (N2RR). For that, this work presents the synthesis and characterization of the layered CZTSSe/CdS/TiO2 photocathode decorated with Pt nanoparticles for application in NH3 production using the photoelectrocatalysis technique. The CZTSSe/CdS/TiO2-Pt characterization showed a well-designed and stable photocatalyst synthesized layer by layer with an important contribution of the Pt nanoparticles for the catalyst performance, improving the photocurrent density and the charge transfer. The N2RR in a two-compartment photochemical cell with 0.1 mol L-1 Na2SO3 and 0.05 mol L-1 H2SO4 in the cathodic and anodic chamber, respectively, using CZTSSe/CdS/TiO2-Pt and under 1 sun of light incidence and applied potential of -0.4 VAg/AgCl reached 0.22 mmol L-1 cm-2 NH3, a value 28 folds higher than using the catalyst without Pt modification. The superiority of N2RR under the photoelectrocatalysis technique was demonstrated compared to photocatalytic and electrocatalytic techniques, together with the investigation of the supporting electrolyte influence in the cathodic compartment. Additionally, that is the first time a kesterite-based photocathode has been applied to NH3 photosynthesis, showing excellent photoconversion capability.

Recent Advances in Electrochemical, Photochemical, and Photoelectrochemical Reduction of CO2 to C2+ Products

Environmental problems such as global warming are one of the most prominent global challenges. Researchers are investigating various methods for decreasing CO₂ emissions. The CO₂ reduction reaction via electrochemical, photochemical, and photoelectrochemical processes has been a popular research topic because the energy it requires can be sourced from renewable sources. The CO₂ reduction reaction converts stable CO₂ molecules into useful products such as CO, CH₄ , C₂ H₄ , and C₂ H₅ OH. To obtain economic benefits from these products, it is important to convert them into hydrocarbons above C₂ . Numerous investigations have demonstrated the uniqueness of the CC coupling reaction of Cu-based catalysts for the conversion of CO₂ into useful hydrocarbons above C₂ for electrocatalysis. Herein, the principle of semiconductors for photocatalysis is briefly introduced, followed by a description of the obstacles for C₂₊ production. This review presents an overview of the mechanism of hydrocarbon formation above C₂ , along with advances in the improvement, direction, and comprehension of the CO₂ reduction reaction via electrochemical, photochemical, and photoelectrochemical processes.

Advances in Biomimetic Photoelectrocatalytic Reduction of Carbon Dioxide

Emerging photoelectrocatalysis (PEC) systems synergize the advantages of electrocatalysis (EC) and photocatalysis (PC) and are considered a green and efficient approach to CO2 conversion. However, improving the selectivity and conversion rate remains a major challenge. Strategies mimicking natural photosynthesis provide a prospective way to convert CO2 with high efficiency. Herein, several typical strategies are described for constructing biomimetic photoelectric functional interfaces; such interfaces include metal cocatalysts/semiconductors, small molecules/semiconductors, molecular catalysts/semiconductors, MOFs/semiconductors, and microorganisms/semiconductors. The biomimetic PEC interface must have enhanced CO2 adsorption capacity, preferentially activate CO2 , and have an efficient conversion ability; with these properties, it can activate CO bonds effectively and promote electron transfer and CC coupling to convert CO2 to single-carbon or multicarbon products. Interfacial electron transfer and proton coupling on the biomimetic PEC interface are also discussed to clarify the mechanism of CO2 reduction. Finally, the existing challenges and perspectives for biomimetic photoelectrocatalytic CO2 reduction are presented.

Light-driven carbon dioxide reduction over the Ag-decorated modified TS-1 zeolite

Cu species doped defective Ag/TS-1 owns Ti3+–Vo which could play an vital part in stabilizing Cu2O. It shows high selectivity for CO and C2H5OH under light excitation and photoelectric condition. The possible pathway of CO2RR process is proposed.