Visible-Light-Driven Inactivation of Bacteria and H2 Generation Catalyzed by Oxygen-Vacancy-Rich One-Dimensional/Two-Dimensional W18O49/g-C3N4 Z-Scheme Heterostructures

Z-scheme heterostructure-based photocatalysts consist of a reduction photocatalyst and an oxidation photocatalyst, enabling them to possess a high capacity for both reduction and oxidation. However, the coupling reaction between photocatalytic H2 generation through water reduction and sterilization using Z-scheme systems has been rarely reported. Herein, 1D W18O49 nanowires embedded over 2D g-C3N4 nanosheets are well-constructed as an integrated Z-scheme heterojunction. Experimental results and density functional theory calculations not only demonstrate the achievement of efficient interfacial charge separation and transport, leading to prolonged lifetime of photogenerated charge carriers, but also directly confirm the mechanism of Z-scheme charge transfer. As expected, the optimized W18O49/g-C3N4 nanostructure exhibits superior photocatalytic sterilization activity against Staphylococcus aureus as well as excellent H2 generation performance under visible-light irradiation (λ ≥ 420 nm). Due to its nontoxic nature, W18O49/g-C3N4 holds great potential in eradicating bacterial infections in living organisms.

Stable and Highly Active Single Atom Configurations for Photocatalytic H2 Generation

The employment of single atoms (SAs), especially Pt SAs, as co-catalysts in photocatalytic H2 generation has gained significant attention due to their exceptional efficiency. However, a major challenge in their application is the light-induced agglomeration of these SAs into less active nanosized particles under photocatalytic conditions. This study addresses the stability and reactivity of Pt SAs on TiO2 surfaces by investigating various post-deposition annealing treatments in air, Ar, and Ar-H2 environments at different temperatures. It is described that annealing in an Ar-H2 atmosphere optimally stabilizes SA configurations, forming stable 2D rafts of assembled SAs ≈0.5-1 nm in diameter. These rafts not only resist light-induced agglomeration but also exhibit significantly enhanced H2 production efficiency. The findings reveal a promising approach to maintaining the high reactivity of Pt SAs while overcoming the critical challenge of their stability under photocatalytic conditions.

Constructing Direct Z-Scheme Heterostructure by Enwrapping ZnIn2 S4 on CdS Hollow Cube for Efficient Photocatalytic H2 Generation

Rational design hybrid nanostructure photocatalysts with efficient charge separation and transfer, and good solar light harvesting ability have critical significance for achieving high solar-to-chemical conversion efficiency. Here a highly active and stable composite photocatalyst is reported by integrating ultrathin ZnIn₂ S₄ nanosheets on surface of hollow CdS cube to form the cube-in-cube structure. Experimental results combined with density functional theory calculations confirm that the Z-scheme ZnIn₂ S₄ /CdS heterojunction is formed, which highly boosts the charge separation and transfer under the local-electric-field at semiconductor/semiconductor interface, and thus prolongs their lifetimes. Moreover, such a structure affords the highly enhanced light-harvesting property. The optimized ZnIn₂ S₄ /CdS nanohybrids exhibit superior H₂ generation rate under visible-light irradiation (λ ≥ 420 nm) with excellent photochemical stability during 20 h continuous operation.