Enhanced the photoelectrochemical performance of BiXO (X = W, Mo) for detecting hexavalent chromium by modification of CuS.

In this work, BiXO (X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of BiWO and BiMoO are 180 and 160°C (BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical (PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by CuS/BiXO (X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1-80 μmol/L with detection limit of 0.95 μmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5-230 μmol/L and a detection limit of 0.12 μmol/L. Thus, 5%-CuS/BiXO has potential application in hexavalent chromium detection.