Engineering interface-mediated heterojunction in MOF-derived C-In2O3 microrods and CdS nanoclusters for enhanced photocatalytic H2O2 production

Abstract

Photocatalysis H2O2 production is recognized a promising route for addressing energy crisis and environmental challenges. However，the photocatalysis efficiency is limited due to the poor charge separation and weak reaction kinetics of water oxidation during the processes of H2O2 production. In this work, we report a rational design of interface-mediated CdS/C-In2O3 heterojunction for boosted H2O2 production under visible light, which was synthesized by MOFs derived C-doped In2O3 (C-In2O3) and strategically integrated with CdS nanoclusters in a simple oil bath process. The unique interfaces in C-In2O3 significantly increase density of accessible active sites for the adsorption and activation of O2. Furthermore, the engineering built-in electric field (BIEF) provided by heterojunction is advantageous for achieving effective regulation of interfacial charge transfer and optimizing two-step 1e- reduction pathway (O2 → ·O2- → H2O2). Notably, the optimal CdS/C-In2O3 demonstrates a remarkably high photocatalytic H2O2 production rate of 2115 μmol·g-1·h-1 and superior selectivity of 88.2%, representing 10.5 times increase compared to bare C-In2O3. The mechanism of highly efficient and robust photocatalytic system tailored for H2O2 production was dual-modification strategy attributed to the synergistic integration of morphology control, interface engineering and heterojunction, achieving enhanced surface area, promoted efficient charge transfer, and increased the adsorption and activation of O2. This work offers valuable insights into the synergistic interplay of interface engineering and heterojunction for the design of In2O3-based photocatalysts with highly efficiency and selective H2O2 production.