Exceeding 0.94% Solar-to-Chemical Energy Conversion: Asymmetrically Charge-Distributed Local Double-Charge Layers for Benzyl Alcohol Oxidation and Hydrogen Coevolution

The large-scale application of solar-powered H 2 evolution technology is restricted by its low efficiency. This study discovered a local double-charge layer (LDCL) electronic structure based on the SiO 2 nanolayer-hindered donor (CdS)-acceptor (Au) photocatalytic system by means of photoexciton tunneling behavior. Electron paramagnetic resonance and femtosecond transient absorption technologies demonstrated the photoexciton tunneling through the SiO 2 nanobarrier, accompanied by hindered photoexciton recombination. Density functional theory calculations proved the asymmetric charge distribution of this LDCL electronic structure, which induced the formation of an e – -rich region on the acceptor Au surface and an h + -rich region near SiO 2 /Au interface for achieving enhanced photoactivity for benzyl alcohol (BA) value-added conversion (20.67 mmol·g –1 ·h –1, nearly 100% benzaldehyde selectivity) and H 2 coevolution (16.88 mmol·g –1 ·h –1 ) due to significantly reduced energy barriers, outperforming most reported catalysts owing to exceeding 0.94% of solar-to-chemical energy conversion. An isotope tracing experiment proved the synergistically enhanced H 2 evolution by the H protons released from BA dehydrogenation. This study proposes a highly advantageous electronic structure for collaborative photocatalysis.