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 BaTiO3/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 BaTiO3/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 BaTiO3/CdS (3.74×10−2 min−1) and BaTiO3 (2.15×10−2 min−1) alone, respectively. In addition, the catalytic rate of BaTiO3/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 BaTiO3/CdS (2.18×10−2 min−1) and BaTiO3 (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 BaTiO3/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.

Doping Sr and Introducing Oxygen Vacancies in Ba0.7Sr0.3TiO3‐X Synergistically Promote the Pyro‐Photo‐Electric Catalysis Performance

“…UV‐visible absorption spectra of BaTiO 3 , Ba 0.7 Sr 0.3 TiO 3 and Ba 0.7 Sr 0.3 TiO 3‐X are shown in Figure 5a and S5. The absorption edge of BaTiO 3 appears at about 391.2 nm, corresponding to the gap of 3.17 eV (the calculation process is shown in formula (2) of support information), which is roughly consistent with the reported results of BaTiO 3 [48,49] . After Sr doping, the absorption edge appears red shift to 403.9 nm.…”

“…The absorption edge of BaTiO 3 appears at about 391.2 nm, corresponding to the gap of 3.17 eV (the calculation process is shown in formula (2) of support information), which is roughly consistent with the reported results of BaTiO 3 . [48,49] After Sr doping, the absorption edge appears red shift to 403.9 nm. The band gap is reduced to 3.07 eV, which is basically consistent with the report of Ba 0.7 Sr 0.3 TiO 3 .…”

Pyroelectric effects in CdS phase junctions for dual-enhanced photocatalytic hydrogen production

“…19 For CdS, the combination of CdS with other different semiconductors has been studied to enhance the pyroelectric properties of materials such as NaNbO 3 /CdS, 20 SnS/CdS, 13 and BaTiO 3 /CdS. 21 In addition, Zhang et al 22 found that CdS nanorods decorated with an organic molecule, 2-mercaptobenzimidazole (2MBI), can greatly enhance the pyroelectric properties and pyroelectric-induced charge separation. At the same time, the surface of CdS has few exposed active sites, limiting the photocatalytic activity, which can be increased by engineering an intimate interface with abundant active sites between a semiconductor and a cocatalyst.…”

Doping regulates pyro-photo-electric catalysis to achieve efficient water splitting in Ba1−xSrxTiO3 through solar energy and thermal resources

“…23,24 Therefore, the enhancement of hydrogen production by photo-electric catalysis water splitting through the pyroelectric effect of pyroelectric materials has attracted wide attention. 25 For example, Zhang et al 26 reported the combination of pyroelectric catalysis and photoelectrochemical catalysis based on NaNbO 3 nanocubes, which realized the energy collection of cold and hot alternate energy and solar energy, and provided reasonable design ideas for the effective design of new environmentally friendly photoelectrodes for PEC water splitting. As mentioned above, it is feasible to improve the photoelectrocatalytic performance by using the pyroelectric effect and combine solar energy, thermal energy and electric energy for water splitting to produce hydrogen.…”