Preparation of Ti4O7/h-BN self-supported ceramic photoelectrode and its photoelectrocatalytic performance for water purification

The construction of high-efficiency self-supported ceramic photoelectrode based on ideal semiconductor materials is essential for achieving effective degradation of pollutants by photoelectrocatalysis (PEC) technology. Herein, a Ti₄O₇/h-BN composite ceramic photoelectrode with a unique microstructure was fabricated by a step-by-step calcination process and used in PEC water pollution remediation. The PEC activity of Ti₄O₇ ceramic photoelectrode could be enhanced by introducing hexagonal boron nitride (h-BN) nanoparticles on the surface. The most optimized Ti₄O₇/h-BN photoelectrode exhibited the decolorization rate of active brilliant blue KN-R at about 97.79% in 30 min. The PEC activities could remain stable during five degradation cycles. The excellent photoelectrocatalytic performance of Ti₄O₇/h-BN ceramic photoelectrode could be attributed to the low Tafel slope, low charge transfer resistance, large electrochemical active area, and excellent photo-generated carrier separation efficiency. A type-II heterojunction was formed between the Ti₄O₇ and h-BN, which caused more effective carrier separation and enhanced the generation of dominant active species •O²⁻ and h⁺. This work provided a mature synthesis strategy of Ti₄O₇/h-BN self-supported ceramic photoelectrodes with excellent practical application prospects to achieve superior PEC performance for water purification.