Ti-doped Bi2(O,S)3 bimetal oxysulfide for highly efficient catalytic reduction of organic dyes and heavy metal pollutants in the dark

A bismuth-titanium bimetal oxysulfide BiTiOS catalyst was prepared via hydrolysis and characterized by different testing techniques. This BiTiOS catalyst, forming the Ti-doped Bi2(O,S)3 phase, can format the oxygen vacancy, increase its electrochemically active surface sites, enhance the electron lifetime, and facilitate fast electron transfer. The BiTiOS catalyst exhibits good electrochemical performance and long-term stability due to its excellent catalytic reduction activity for toxic organic of p-nitrophenol, organic dyes of methyl orange, methylene blue, and rhodamine, and the heavy metal ion of Cr(VI) in the presence of NaBH4 in the dark. The BiTiOS catalyst with the best reduction activity was prepared at a molar ratio of n(Bi): n(Ti): n(TAA) at 1: 2: 4. The 100 mL for each 20 ppm MO, MB, RhB, and 4-NP was reduced entirely in 4, 4, 2, and 8 min, respectively. In comparison, the reduction of 100 mL of 50 ppm Cr(VI) took 22 min. The BiTiOS-2 catalyst, showing fast reduction efficiency and excellent stability and durability, is expected to have great potential in wastewater treatment.