The charge separation/transport efficiency is relatively high in thin-film hematite photoanodes in which the distance for charge transport is short, but simultaneously the high loss of light absorption due to transmission is confronted. To increase light absorption in thin-film Fe2O3:Ti, commercial substrates such as Cu foil, Ag foil, and a mirror are adopted acting as back-reflectors and individually integrated with the Fe2O3:Ti electrode. The promotion effect of the commercial back-reflectors on the light absorption efficiency and photoelectrochemical (PEC) performance of the hydrothermally prepared Fe2O3:Ti electrodes with a variety of film thicknesses is investigated. As a result, Ag foil and the mirror show favorable and equal efficacy while the promoting effect of Cu foil is limited. In addition, the photocurrent increment achieved by the Ag back-reflector decreases linearly along with the logarithmic of the film thickness and the optimized film thickness of the Fe2O3:Ti electrode is decreased from 520 to 290 nm. The high durability of Ag foil in the alkaline electrolyte during solar light irradiation is demonstrated. Furthermore, the reflective substrate also shows a promotion effect on the BiVO4 photoanode and CuBi2O4 photocathode, as well as the unbiased photocurrent from a tandem cell constituted by TiO2 and CuBi2O4.
Min Jiang,Xiangyu Wang,Renchan Han,Ping Ning,Iseult Lynch,Jun Ma
A S-scheme Fe/Fe 2 O 3 @CBO photocatalyst was synthesized via a grinding calcination method, proficiently degrading tetracycline via radicals and non-radical. The reaction rate of Fe/Fe 2 O 3 @CBO-20 was recovered to 0.0255 min −1 that is 4.3 and 7.3 times as many as pristine Fe/Fe 2 O 3 and CBO after introducing visible light at the degradation process. The characterization outcomes also bear out that the S-scheme heterojunction is formed by passivation layer Fe 2 O 3 and CBO, which enhances the visible light responsiveness of catalyst and promotes the separation and transfer of photogenerated electrons to generate h + and O 2 − . Meanwhile, the molecular oxygen is more easily activated to form H 2 O 2 due to the strong reduction potential of the CB (−1.21 eV), further to facilitate the transformation of O 2 − to 1 O 2 . And the carriers excited in CBO activate Cu + , forming a Cu/Fe dual-metal electron cycle. The generated Fe 2+ reacts with H 2 O 2 to establish photocatalysis-self-Fenton system to generate ·OH. Additionally, the high TC removal in simulated aquatic environment exhibit that the catalytic performance is slightly affected by practical wastewater and the cyclic experiment show the stability and practicality. In conclusion, innovatively employing Fe/Fe 2 O 3 for pollutant degradation via photocatalytic technology, this research paves a promising and efficacious pathway for the application of Fe/Fe 2 O 3 .