Spatial Specific Janus S-Scheme Photocatalyst with Enhanced H 2 O 2 Production Performance.

Photocatalytic oxygen reduction reaction (ORR) for H 2 O 2 production in the absence of sacrificing agents is a green approach and of great significance, where the design of photocatalysts with high performance is the central task. Herein, a spatial specific S-scheme heterojunction design by introducing a novel semiconducting pair with a S-scheme mechanism in a purpose-designed Janus core-shell-structured hollow morphology is reported. In this design, TiO 2 nanocrystals are grown inside the inner wall of resorcinol-formaldehyde (RF) resin hollow nanocakes with a reverse bumpy ball morphology (TiO 2 @RF). The S-scheme heterojunction preserves the high redox ability of the TiO 2 and RF pair, the spatial specific Janus design enhances the charge separation, promotes active site exposure, and reduces the H 2 O 2 decomposition to a large extent. The TiO 2 @RF photocatalyst shows a high H 2 O 2 yield of 66.6 mM g -1  h -1 and solar-to-chemical conversion efficiency of 1.11%, superior to another Janus structure (RF@TiO 2 ) with the same heterojunction but a reversed Janus spatial arrangement, and most reported photocatalysts under similar reaction conditions. The work has paved the way toward the design of next-generation photocatalysts for green synthesis of H 2 O 2 production.