Exceptional Visible-Light Photoelectrocatalytic Activity of Z-Scheme Bi@Bioi-Bi2o3/C3n4 Heterojunction for Simultaneous Remediation of Cr(Vi) and Phenol

Developing highly efficient and stable photocatalysts remains a major challenge for the remediation of environmental pollutants. In this work, a Bi0 decorated BiOI-Bi2O3/C3N4 heterojunction (Bi@BiOI-Bi2O3/C3N4) film was fabricated through ultrasonic stripping, I− etching and in situ UV-reduction processes and then characterized thoroughly by various analytical techniques. The characteristics of simultaneous photoelectrocatalytic (PEC) mitigation of phenol and Cr(VI) were evaluated over Bi@BiOI-Bi2O3/C3N4 photoanode under visible light. The results exhibited that both phenol and Cr(VI) were removed completely by the photoanode at 2.5 V potential within 1.5 h, superior to our previous report. The synergistic effect of Bi0 and Z-scheme heterojunction accelerated the separation and transfer of photo-induced charge carrier and thus heavily promoted the removal efficiency. Moreover, the excellent stability of this photoanode was hold with no considerably activity attenuation after 4 cycles. A simultaneous PEC remediation mechanism of phenol and Cr(VI) was also presented. The findings offer an attractive pathway to construct highly active photoelectrode with promising application for simultaneous remediation of organics and heavy metals in wastewater.