Design, Synthesis, and Diverse Applications of Cu-Based Photocatalysts: A Review

With the increasing variety of Cu-based semiconductor nanomaterials and the development of synthesis technology, the crystal shape and morphology of semiconductor materials have become controllable factors. Due to their low price, abundant reserves, and suitable band gap, Cu-based semiconductor nanomaterials have bright application prospects for the treatment of photocatalytic environments. A comprehensive summary of the basic theory and research progress of Cu-based semiconductor nanomaterials, such as crystal design, morphology control, and photocatalytic modification strategies and mechanisms, is indispensable. However, a comprehensive review of this aspect has not been reported recently. This review summarizes the synthetic methods of copper oxides (CuO, Cu2O), copper sulfides (CuS, CuxS, Cu2S), copper selenides (CuSe, Cu2–xSe, Cu2Se), as well as other novel Cu-based semiconductor nanomaterials such as CuFe2O4, Cu3N, Cu5V2O10, CuCo2O4, CuWO4, Cu3P, and the application strategies and mechanisms in photocatalytic removal of pollutants, photocatalytic hydrogen evolution, and photocatalytic reduction of CO2. The summary of synthesis methods and crystal surface control is beneficial for the preparation of better catalysts. We firmly believe that this review can provide valuable information for the further development of Cu-based semiconductor nanomaterials.