CuO Nanoparticle‐Loaded TiO ₂ Catalyst for High‐Performance Photocatalytic Hydrogen Peroxide Generation

Abstract Titanium dioxide (TiO ₂ ) has been extensively investigated in photocatalysis due to its high stability, low toxicity, and biocompatibility. However, its application in hydrogen peroxide (H ₂ O ₂ ) production is hindered by the rapid recombination of photogenerated charge carriers and the poor selectivity of the two‐electron oxygen reduction reaction (2e ⁻ ORR). Here, a CuO/TiO ₂ photocatalyst is reported, in which CuO nanoparticles are anchored on the TiO ₂ surface as cocatalysts to provide additional active sites and promote efficient separation of photogenerated electrons and holes. The optimized CuO/TiO ₂ exhibits a remarkable photocatalytic H ₂ O ₂ production rate of 19.48 mmol g ⁻¹ h ⁻¹ , which is 162 times higher than that of pristine TiO ₂ , with excellent stability sustained over 7 h’ continuous irradiation. The apparent quantum yield (AQY) of CuO/TiO ₂ reaches 7.30% at 365 nm. Notably, the CuO/TiO ₂ demonstrated the promising H ₂ O ₂ production in pure water (182.31 µmol g ⁻¹ h ⁻¹ ). Femtosecond transient absorption spectra (Fs‐TAS) reveal that the average lifetime of photogenerated electrons in CuO/TiO ₂ is 5.8 times longer than in TiO ₂ , confirming the enhanced charge separation and transfer. In situ spectroscopic analyses further demonstrate that CuO/TiO ₂ facilitates both oxygen reduction and water oxidation pathways. These results highlight CuO/TiO ₂ as a cost‐effective and efficient photocatalyst for sustainable H ₂ O ₂ production.