Fabrication of flexible Cu-TiO2 nanosheet photocatalysts on carbon cloth for solar hydrogen production via a self-healing Cu redox loop

Abstract

The development of sustainable photocatalysts for solar to hydrogen (STH) remains a central challenge in clean energy research. Here, binder-free Cu-doped TiO₂ nanosheets on conductive carbon cloth (Cu-TNS@CC) are fabricated and tested as a photocatalyst for STH. The optimized Cu-TNS@CC delivers a hydrogen evolution rate of 1765 µmol g⁻¹ h⁻¹, nearly seven times higher than that of pristine TiO₂@CC. Spectroscopic and structural analyses reveal the first evidence of a dynamic Cu⁰ ⇌ Cu⁺ ⇌ Cu²⁺ self-healing redox loop on any substrate, which leads to regeneration of active Cu₂O and prevents its deactivation with >98% stability over 20 hours of operation. These findings provide insightful knowledge of a redox self-healing Cu photocatalyst platform for sustainable solar hydrogen production.