Construction of Ti3+ self-doped TiO2/BCN heterojunction with enhanced photoelectrochemical performance for water splitting

Ti3+ self-doped TiO2/BCN heterojunction (Ti3+-TiO2/BCN) was constructed via a hydrothermal method with using NaBH4 as reducing agent. The BCN nanosheets function as a good support to block the agglomeration of Ti3+-TiO2 nanoparticles, which decreased the recombination of photogenerated charge carriers. The Ti3+-TiO2/BCN sample exhibited enhanced electronic conductivity and absorption in visible light region because of the introduction of Ti3+ and oxygen vacancies (Ov). The as-prepared Ti3+-TiO2/BCN sample showed enhanced photoelectrochemical (PEC) performance as confirmed by analyses of LSV, EIS, Bode plots and M–S. Under the visible light irradiation, the optimally Ti3+ self-doped TiO2/BCN heterojunction sample yield a photocurrent density of ∼ 0.69 mA/cm2 at 1.23 V versus RHE, which is over three times as high as BCN and TiO2/BCN at the same conditions.