Efficient hydrogen peroxide production: Enhancing electron transfer on PANI/CdS photocatalysts in aqueous solution

The conventional anthraquinone process for hydrogen peroxide production is energy-intensive and complex. We present a sustainable alternative: a photocatalytic technology driven by solar energy for the green and efficient generation of H2O2. In this study, we synthesized polyaniline (PANI), a conductive polymer, and combined it with CdS nanoparticles (CdS-NP) using a hydrothermal method to create PANI/CdS-NP composites. The unique hollow raspberry-like structure of the composite enhances light utilization through multiple reflections and refractions. PANI significantly improved the photoresponse and photocatalytic activity of CdS-NP. Under visible light and an air flow of 20 mL·min-1, the 10 wt%-PANI/CdS-NP composite exhibited a remarkable photocatalytic hydrogen peroxide production rate of 371.33 μmol·h−1·g−1, surpassing the pristine CdS-NP by 1.74 times, and all without any sacrificial agents. Work function calculations revealed that the electron transport between CdS and PANI follows the type II heterojunction photocatalytic mechanism, with the one-step two-electron ORR being the dominant pathway. This work not only contributes to the theoretical understanding of photocatalytic H2O2 synthesis but also offers a promising route toward the green and sustainable production of H2O2. [Display omitted] •PANI/CdS-NP composite boosts H2O2 production rate to 371.33 μmol·h−1·g−1, a 74 % improvement over CdS-NP.•Hollow raspberry-like structure enhances light utilization.•PANI improves photoresponse, facilitating charge separation & efficient electron transfer.•Work function calculation reveals type II heterojunction path, favoring one-step two-electron ORR for H2O2.