Ag Nanoparticle-Decorated GaN/β-Ga₂O₃ Core–Shell Nanowires as Catalysts for Highly Efficient CO₂-to-CO Photocatalytic Conversion

Abstract

Solar-driven photocatalytic CO 2 conversion is a promising strategy to alleviate the energy crisis and reduce the level of CO 2 emissions. In this study, GaN@β-Ga 2 O 3 core−shell nanowire (NW) arrays were prepared via the thermal oxidation of GaN NWs, and their photocatalytic CO 2 reduction performance was investigated. GaN@β-Ga 2 O 3 NWs exhibited superior photocatalytic activity compared to GaN NWs and β-Ga 2 O 3 NWs under simulated sunlight irradiation. The average CO production rate reached ∼447.30 μmol g −1 h −1 within 3 h. The photocatalytic reduction process was further enhanced using GaN@β-Ga 2 O 3 NWs with Ag nanoparticles of ∼18 nm size as cocatalysts, and its average rate increased to ∼689.18 μmol g −1 h −1 . The ternary heterostructured photocatalyst demonstrated excellent synergistic effects and high efficiency in environmental protection and energy conversion applications.

Pt/BiOBr Nanocomposite Supported on Graphdiyne for the Selective Photoreduction of CO2 into Hydrocarbons

“…C 2 or C 2+ hydrocarbons are generated on the modified catalysts by means of vacancy regulation, single-atom load, valence transformation, surface reconstruction, etc. − However, controlled C–C coupling to produce high-value C 2 or C 2+ products still remains a great challenge. The photocatalytic CO 2 reduction into hydrocarbons involves a complex process of multielectron coupled proton transfer, necessitating the active participation of sufficient light-induced electrons in the photocatalytic reduction process. , Furthermore, it also requires overcoming the activation of the CO bond and the coupling kinetics of the C–C bond in order to convert CO 2 into certain hydrocarbons. , Despite some semiconductor catalysts exhibiting a promising performance in the photocatalytic CO 2 hydrogenation into hydrocarbons, the selectivity of hydrocarbons in the resulting products remains lower than that of carbon monoxide. − This is mainly because of the low surface charge density on photocatalysts, making it difficult to overcome the energy barrier associated with C–C coupling. Therefore, increasing the surface charge density and lowering the energy barrier associated with C–C coupling are the keys to boost photocatalytic CO 2 conversion to C 2+ hydrocarbons.…”