Construction of a photocatalytic fuel cell using a novel Z-scheme MoS2/rGO/Bi2S3 as electrode degraded antibiotic wastewater

Abstract

• A Z-scheme MoS 2 /rGO/Bi 2 S 3 was first fabricated and the PFC system was construction. • The MoS 2 /rGO/Bi 2 S 3 composite shows a better photoelectrochemical properties. • A high-efficiency degradation of antibiotic wastewater was realized in the PFC. • The electron generated and transport mechanism in the PFC were proposed. Using a Z-scheme MoS 2 /rGO/Bi 2 S 3 loaded onto carbon felt (CF) as the anode and BiOBr as the cathode in a photocatalytic fuel cell (PFC) was found to be an efficient photocatalytic system for degrading water contaminants such as antibiotics. Some standard analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible spectrophotometry (UV–Vis DRS), ultraviolet photoelectron spectroscopy (UPS), electron paramagnetic resonance (EPR), high performance liquid chromatography-mass spectrometry (HPLC-MS) and electrochemical analysis (cyclic voltammetry, CV and current-time curve, I-t ), were applied to characterize the diverse properties of the electrodes. First, two typical antibiotic contaminants, berberine chloride (BEC) and tetracycline hydrochloride (TC), were used to investigate the degradation ability of the electrodes. As expected, results showed that the degradation of TC and BEC using MoS 2 /rGO/Bi 2 S 3 @CF was consistently above 90%, whereas the degradation achieved by independently using rGO/Bi 2 S 3 @CF and rGO/MoS 2 @CF was consistently below 85% and as low as 53%; this verified the excellent formation of the heterojunction. In addition, to further investigate the performance of MoS 2 /rGO/Bi 2 S 3 @CF, the test results under different conditions were discussed, such as pH, electrochemical property, light reactivity, dark absorption and recyclability in depth. All results of MoS 2 /rGO/Bi 2 S 3 @CF demonstrated good performance than rGO/Bi 2 S 3 @CF and rGO/MoS 2 @CF. Based on the UV–Vis DRS, UPS, EPR and trapping agent experiment results, the electron generated and Z-scheme transport mechanism in the fuel cell was proposed. Moreover, electron transmission from MoS 2 /rGO/Bi 2 S 3 @CF to BiOBr@CF through an external circuit further suppressed the recombination of electron-hole pairs. This new catalytic pollution control route is expected to provide a new way for efficient pollutant degradation with low energy consumption.