Activation of Cu3(Moo4)2(Oh)2 with the Hydrazine-Driven Cation Reduction into a Highly Efficient Catalyst for the Reduction of Organic Dyes and Heavy Metals Ion

Abstract

Monoclinic lindgrenite (Cu3(MoO4)2(OH)2)-like CuMoOS oxysulfide catalyst with high catalytic activity in the dark was synthesized by a facile method. Sulfur doping was used to diminishe the problem of poor stability caused by the excessive deviations of the catalyst from electric neutrality due to the high Cu+ and Mo4+ concentrations. The ratios of Cu+/Cu2+ and Mo4+/Mo6+ ions affected the catalytic activity of CuMoOS catalysts. The CuMoOS with a Cu+/(Cu++Cu2+) ratio of 0.708 showed abundant oxygen vacancies and the best catalytic reduction effect. Through controlling the Cu+ content of the catalyst, its defective structure, and electron transfer resistance, the reduction reaction can be effectively adjusted. CuMoOS-3 catalyst completely reduced 50 ppm of 4-NP in 4 min. 50 ppm MB, RhB and MO organic dyes were completely reduced in 4 min, 6 min, and 8 min, respectively. At the same time, Cr6+, as a model heavy metal ion, was completely reduced in 12 min, and its pseudo-first-order reaction kinetic constant reached 0.1709 min-1. Good stability was kept after six cycling experiments. Therefore, the high-efficiency CuMoOS catalyst synthesized by green procedures displays the potential for industrial application.

Keywords: Pollutants reduction, Oxysulfide, Catalysis, Oxygen vacancy