Hengxin Ren,Xinyu Sun,Tong Li,Zhixin Ren,Chaoyu Song,Yuguang Lv,Ying Wang
Herein, a new Z-scheme BiVO4/Cu2O/PPy heterostructure photocatalyst was developed with bismuth nitrate and ammonium vanadate as the precursors and sodium dodecyl benzyl sulfonate as the soft template. Through the spatial confinement effect of the sodium dodecyl benzyl sulfonate soft template, peanut-like BiVO4 and the BiVO4/Cu2O/PPy heterojunction were synthesized. The best performance was observed for BiVO4/Cu2O/PPy (5%), and its photodegradation rate was 6.57 times higher than that of pure BiVO4. The mechanism study showed that a light hole (h+), superoxide radical (·O2−), and hydroxyl radical (·OH) participated in the CO2 reduction process, which was different from the pure BiVO4 reaction system. Therefore, the proposed approach provides a new method for applying BiVO4/Cu2O/PPy photocatalysts and developing the same type of heterojunction photocatalyst, and they have effective practical application for environmental remediation.
The serious recombination of photogenerated carriers and the photochemical corrosion of the electrode extremely restricted its photoelectrochemical (PEC) performance, which could not reach the theoretical photocurrent intensity. However, so far, there are few comprehensive reports on the mechanism of corrosion inhibition and stability improvement of electrodes in photocatalytic degradation. In this paper, BiVO 4 /Cu 2 O heterojunction modified by Cobalt-phosphate (Co-Pi) co-catalyst was successfully prepared to address the aforementioned issues. Co-Pi completed the holes capture and release process through the change of its own chemical state (Co 2+/3+ →Co 4+ →Co 2+/3+ ), and also affected the energy band bending of the BiVO 4 /Cu 2 O heterojunction. In addition, the effect mechanism of the Co-Pi film thickness on the PEC performance of the photoanode was systematically discussed in this report. When the deposition amount was 0.05C∙cm −2 , the photocurrent density reached 2.22 mA∙cm −2 at 1.23 V (vs. RHE), which was 2.8 times that of bare BiVO 4 . The LSV curves, EIS and UV–vis absorption spectra reveal the enhanced PEC performance and light stability of the prepared electrode materials. When it is applied to photocatalytic degradation of organic pollutants, BiVO 4 /Cu 2 O/0.05Co-Pi shows high activity and potential for MB and CIP degradation, and is expected to be stably applied to the field of photocatalytic degradation of refractory organic pollutants in water.