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 optimised Cu–TNS@CC delivers a hydrogen evolution rate of 1765 µmol g⁻¹ h⁻¹, nearly seven times higher than pristine TiO₂@CC. Spectroscopic and structural analyses reveal the first evidence of a dynamic Cu⁰⇌Cu⁺⇌Cu²⁺ self-healing redox loop at 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 redox self-healing Cu photocatalyst platform for sustainable solar hydrogen production.