Overall photosynthesis of H2O2 by an inorganic semiconductor

Abstract

Artificial photosynthesis of H2O2 using earth-abundant water and oxygen is a promising approach to achieve scalable and cost-effective solar fuel production. Recent studies on this topic have made significant progress, yet are mainly focused on using organic polymers. This set of photocatalysts is susceptible to potent oxidants (e.g. hydroxyl radical) that are inevitably formed during H2O2 generation. Here, we report an inorganic Mo-doped faceted BiVO4 (Mo:BiVO4) system that is resistant to radical oxidation and exhibits a high overall H2O2 photosynthesis efficiency among inorganic photocatalysts, with an apparent quantum yield of 1.2% and a solar-to-chemical conversion efficiency of 0.29% at full spectrum, as well as an apparent quantum yield of 5.8% at 420 nm. The surface-reaction kinetics and selectivity of Mo:BiVO4 were tuned by precisely loading CoOx and Pd on {110} and {010} facets, respectively. Time-resolved spectroscopic investigations of photocarriers suggest that depositing select cocatalysts on distinct facet tailored the interfacial energetics between {110} and {010} facets and enhanced charge separation in Mo:BiVO4, therefore overcoming a key challenge in developing efficient inorganic photocatalysts. The promising H2O2 generation efficiency achieved by delicate design of catalyst spatial and electronic structures sheds light on applying robust inorganic particulate photocatalysts to artificial photosynthesis of H2O2.

A general interfacial-energetics-tuning strategy for enhanced artificial photosynthesis

“…S3) show that the BiVO4 particles exhibit a decahedron structure with clear facets. Following previous studies, 18,19 the top/bottom and side facets are assigned to {010} reduction facets and {110} oxidation facets, respectively.…”

Reaction Pathways toward Sustainable Photosynthesis of Hydrogen Peroxide by Polymer Photocatalysts

“…Two electrons and two protons are consumed simultaneously to generate H 2 O 2 . This reaction pathway has now been found in various photocatalysts. − g -C 3 N 4 is the first polymer photocatalyst to exhibit high selectivity (90%) toward photocatalytic H 2 O 2 production via the direct two-electron ORR pathway (Figure a) . Based on Raman and electron spin resonance (ESR) spectroscopic characterizations, it was shown that the high H 2 O 2 selectivity was attributed to the formation of 1,4-endoperoxide species on the heptazine structure (Figure b).…”

Construction of a Bi2MoO6/CoOx/Au system with a dual-channel charge transfer path for enhanced tetracycline degradation

“…The peaks centered at 780.6 eV and 796.3 eV could be ascribed to Co 3+ , while the peaks at 782.0 eV and 797.3 eV could be attributed to Co 2+ . 53,61,67 Thus, the mixed chemical states present in the Co species of the composites and the cocatalyst should be denoted as CoO x .…”

“…Considering the advantages of CoO x and Au, a dual-channel charge carrier transfer path could be established. [51][52][53] Moreover, combined with the features of extended interface contact areas and decreased charge transfer time, 2D BMO could further accelerate the migration of charge carriers. In a nutshell, we believe that the introduction of CoO x and Au on 2D BMO nanosheets provides an unprecedented opportunity to restrain the recombination of photogenerated electrons and holes.…”