Enhanced photocatalytic activity over a novel CuWO₄/Cu_1-xZn_xWO₄/ZnWO₄ hybrid material with sandwiched heterojunction

A novel CuWO4/Cu1-xZn xWO4/ZnWO4 hybrid photocatalyst with sandwiched heterojunction structure was prepared by a one-port synthesis with Zn doping into CuWO4. The crystalline structure, optical, and morphological properties as well as photocatalytic performance of the as-prepared hybrid photocatalyst were studied. By adjusting the amount of Zn doped, the optimal doping level was determined to be 0.1 wt% Zn²⁺. More than 80% photocataytic degradation of rhodamine B was achieved within 20 min over 0.1 wt% Zn²⁺ doped CuWO4, while only 20% was achieved for the pure CuWO4. The enhancement was proposed to be due to the formation of a CuWO4/Cu1-xZn xWO4/ZnWO4 sandwiched heterojunction. Such tandem type heterojunction was found to be efficient for charge separation compared to traditional single heterojunction, which, in turn, resulted in a significantly enhanced photocatalytic activity. Our finding is also expected to be valuable for the exploration of CuWO4-material as a new group of efficient photocatalysts.