Acetate improves catalytic performance for rapid removal of Cr(VI) by sodium borohydride in aqueous environments

One-Step Synthesis of Nitrogen-Doped Porous Biochar Based on N-Doping Co-Activation Method and Its Application in Water Pollutants Control

“…Conversely, when the pH was higher than 6 (particularly 8), the protonation of the dye was gradually weakened, and the biochars with negative active sites on the surface were not conducive to the adsorption of anionic dyes due to electrostatic repulsion, which reduced the adsorption amount of MO. Cr 6+ also possessed various forms at different pH levels [ 4 , 5 , 20 ], where it exists as HCrO 4 − and Cr 2 O 7 2− when the pH is lower than 6.5, and as Cr 2 O 7 2− and CrO 4 2− when the pH is higher than 6.5. With the increase in pH, the adsorption capacities of both BBB and N-BBB decreased, and the maximum adsorption capacities were at a pH value of 2.…”

“…Because of its high solubility, easy accumulation, and difficulty degrading in the ecosystem, Cr 6+ is one of the main toxic heavy metals that pollute water bodies [ 4 ]. Cr 6+ ions are discharged into the water in large quantities during industrial processes such as metallurgy and electroplating [ 5 ]. Similarly, synthetic dyes are widely used in the printing, dyeing, and textile industries [ 6 ].…”

Cobalt oxide decked with inorganic-sulfur containing vanadium oxide for chromium(vi) reduction and UV-light-assisted methyl orange degradation

“…[11][12][13][14][15][16][17] The reduction processes employ reducing agents like sodium borohydride (NaBH 4 ) and ascorbic acid which are considered to be effective in the presence of suitable materials for the conversion of Cr(VI) to Cr(III). [18][19][20][21] As far as the materials are concerned, sulfur-containing transition metals or the metal chalcogenides have shown some promising activity in the removal of Cr(VI). [22][23][24][25][26] Our group has also reported a silver-sulfur-oxido-vanadium cluster for such a reduction process within a very short period of time with NaBH 4 as a reducing agent.…”

“…Our previous studies and various other literature reports predicted that NaBH 4 served as a suitable reducing agent with an active catalyst for Cr(VI) reduction. 18,19,27 Therefore, considering 0.1 mmol of NaBH 4 , 10 mL of Cr(VI) solution and 2 mg of CoO x -S-VO x catalyst, essential reaction parameters (time, NaBH 4 amount, and catalyst amount) were optimized for Cr(VI) reduction. From the graph shown in Fig.…”