Thermal Excitation Polarized Field Drives Photoelectric Catalysis for Dye Degradation in a BaTiO3/CdS Heterojunction through Integration of Solar and Thermal Energy

Abstract Efficient charges separation and transfer are considered to be the key factors to achieve high efficiency photoelectric catalysis. Herein, we proposed that the internal potential difference and the macroscopic polarization field of the homotype BaTiO 3 /CdS pyroelectric heterojunction can adjust the photoelectric catalytic performance to achieve degradation of methylene blue (MB) and rhodamine B (RhB) dyes. Under 20–50 °C hot–cold cycles, light and external bias, the catalytic rate of BaTiO 3 /CdS for MB is 4.82×10 −2 min −1 , which is 1.29 times and 1.36 times higher than photoelectric catalytic rates of BaTiO 3 /CdS (3.74×10 −2 min −1 ) and BaTiO 3 (2.15×10 −2 min −1 ) alone, respectively. In addition, the catalytic rate of BaTiO 3 /CdS for RhB is 3.07×10 −2 min −1 , which is 1.41 times and 1.28 times higher than photoelectric catalytic rates of BaTiO 3 /CdS (2.18×10 −2 min −1 ) and BaTiO 3 (1.45×10 −2 min −1 ) alone, respectively. The improvement of catalytic efficiency is due to the generation of pyrogenerated and photogenerated carriers, and the macroscopic polarization field and the potential difference at the BaTiO 3 /CdS heterojunction interface can enhance the separation and transfer of charge. This study confirms that the homotype heterojunction based on the pyroelectric effect can use solar/thermal energy to achieve efficient photoelectric catalysis. This provides a reference for the design and development of new and efficient electrodes in the field of photoelectric catalysis.