Enhanced photoelectrochemical water splitting coupled with pharmaceutical pollutants degradation on Zr:BiVO₄ photoanodes by synergetic catalytic activity of NiFeOOH nanostructures

Globally, the emergence of drug-resistant bacteria has created an urgent need for an effective method to remove antibiotics from pharmaceutical wastewater. Engineering Bismuth vanadate (BiVO₄) with an oxygen evolution cocatalyst (OEC) holds a promising potential for enhancing water splitting efficiency in the production of hydrogen (H₂) using free solar energy. Here, we successfully developed a Zr:BiVO₄/NiFeOOH heterojunction by electrodeposition and photoelectrochemical transformation. Zr:BiVO₄/NiFeOOH photoanodes exhibit 5 fold superior photocurrent response at 1.23 V compared with Zr:BiVO₄ electrodes, since NiFeOOH acts as an oxygen-releasing catalyst. Furthermore, the attained heterojunctioned electrode can effectively degrade TCH, riboflavin, and streptomycin in PEC. The degradation rate of TCH acquired 96% within 1 h, which is 3 times superior than the efficiency reported for pristine Zr:BiVO₄ photoelectrodes. By introducing NiFeOOH into BiVO₄, electron life-time was increased and electron-hole recombination was suppressed. In this study, we present a solar-driven, sustainable and effective way of treating wastewater and provide new insights into the process.