Design and construction of high performance semiconductor photo/electro-catalytic systems and devices based on the theory of semiconductor energy band and crystal phase engineering: 1. Development of transition metal sulfide semiconductor materials. 2. Application of non-metallic semiconductor materials. 3. Design of MXenes carbide photo/electro-catalytic material. 4. Stripping and preparation of semiconductor two-dimensional materials. 5. Photo/electro-catalytic mechanism analysis and research.