Obvious enhancement of visible photocatalytic performance of Cu2O modified with TiO2-g-C3N4: A strategy to achieve synergistic effect of p-n junction and Z-scheme

Abstract

The Cu2O–TiO2-g-C3N4 (C-TCN) composite photocatalysts which have excellent photocatalytic properties was synthesized via facile calcination and hydrothermal technique. The composition, morphology and structure of the synthetic materials were investigated by a series of characterizations. The results exhibited that TiO2-g-C3N4 (TCN) modified Cu2O ternary composites were successfully prepared. The photo-degradation rate of methyl orange (MO) dye and tetracycline hydrochloride (TC) were 95.08% and 93.28% in the presence of the C-TCN photocatalysts under visible-light. The dramatically increase of photocatalytic properties of ternary composites was assumed to g-C3N4 functioned as the ladder and relay station between TiO2 and Cu2O, which could simultaneously create p-n conjunction between Cu2O and g-C3N4 and Z-scheme between Cu2O and TiO2. The free radical quenching experiment and ESR detection verified that •O2− and •OH were the core redox species in the visible photocatalysis process. This paper demonstrate a feasible idea for synthesizing Cu2O based multi-component composites with dramatically improved visible photocatalytic properties.