Crystal-Structure-Dependent Photocatalytic Redox Activity and Reaction Pathways over Ga2O3 Polymorphs

Investigation of catalytic methane oxidation over Ag/Co2MOx (M = Co, Ni, Cu) catalysts with varying interfacial electron transfer

Atom-doped Co3O4 catalysts loaded with Ag were examined as cost-effective catalysts for methane oxidation. The synthesized Ag/Co2NiOx catalysts exhibited distinctive surface characteristics in contrast with Ag/Co3O4 and Ag/Co2CuOx catalysts prepared using a similar method. Characterization results unveiled that Ag/Co2NiOx featured a higher presence of active surface oxygen species, lattice defects, a larger surface area, and enhanced reducibility. A methane oxidation catalytic performance followed the sequence: Ag/Co2NiOx > Ag/Co3O4 > Ag/Co2CuOx. The investigation delved into methane degradation pathways on the surfaces of three catalysts, examining their behavior under both aerobic and anaerobic atmospheres through in-situ DRIFTS analysis. Furthermore, introducing Ag showed a marked positive effect on Co-Ni mixed oxide, inducing electron transfer and a more active electron system, whereas it exhibited an inverse impact within the surface of Co-Cu mixed oxide. This work provides innovative perspectives on the development of forthcoming environmental catalysts.

Understanding the Behaviors of Plasmon-Induced Hot Carriers and Their Applications in Photocatalysis

Photocatalysis driven by plasmon-induced hot carriers has been gaining increasing attention. Recent studies have demonstrated that plasmon-induced hot carriers can directly participate in photocatalytic reactions, leading to great enhancement in solar energy conversion efficiency, by improving the catalytic activity or changing selectivity. Nevertheless, the utilization efficiency of hot carriers remains unsatisfactory. Therefore, how to correctly understand the generation and transfer process of hot carriers, as well as accurately differentiate between the possible mechanisms, have become a key point of attention. In this review, we overview the fundamental processes and mechanisms underlying hot carrier generation and transport, followed by highlighting the importance of hot carrier monitoring methods and related photocatalytic reactions. Furthermore, possible strategies for the further characterization of plasmon-induced hot carriers and boosting their utilization efficiency have been proposed. We hope that a comprehensive understanding of the fundamental behaviors of hot carriers can aid in designing more efficient photocatalysts for plasmon-induced photocatalytic reactions.

Unravelling the surface structure of β-Ga2O3 (100)

The present work is on a comprehensive surface atomic structure investigation of β-Ga2O3 (100). The β-Ga2O3 single crystal was studied by a structural model system in the simulations and in situ characterization via X-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED) and X-ray photoelectron diffraction (XPD) allowed for probing the outermost layers' properties. In situ XPD characterization allows for the collection of valuable element-specific short-range information from the β-Ga2O3 surface, and the results were compared to a systematic and precise multiple scattering simulation approach. The experiments, characterizations, and simulations indicated strong evidence of considerable structural variations in the interatomic layer's distances. Such atomic displacement could clarify the electronic phenomena observed in theoretical studies. The comparison between experimental and theoretical XPD results involving multiple scattering calculations indicated that the β-Ga2O3 surface has two possible terminations. The best fits to the photoelectron diffraction curves are used to calculate the interplanar relaxation in the first five atomic layers. The results show good agreement with previous density functional theory calculations, establishing XPD as a useful tool for probing the atomic structure of oxide surfaces.