CuS Nanoparticles Trigger Sulfite for Fast Degradation of Organic Dyes under Dark Conditions

Abstract

CuS nanoparticles (CuS NPs) were synthesized by a simple precipitation method using rice starch water as a capping and reducing agent. The phase composition, morphology, absorbance, chemical bonds, and chemical states of the CuS NPs were investigated systematically and then examined for dye degradation catalytic activity with or without sulfite (SO 3 2− ) under dark conditions. Herein, we observed two reaction trends after the addition of SO 3 2− in a CuS NPs/dye system, first substantially enhanced dye degradation and second greater degradation activity between reaction time interval "t" 0−12 min. The redox cycling of Cu(II)/Cu(I) and oxidized sulfur (SO x 2− ) species on the surface of CuS NPs played a major role for the activation of SO 3 2− and generation and transformation of a sulfite radicalScavenging studies of reactive oxygen species (ROS) revealed that • SO 4 − was major reactive species involved in dye degradation. Our study showed that SO 3 2− acted as a source and CuS NP surface acted as an SO 3 2− activating agent for the generation of • SO 4 − , which degrades the dyes. The activation pathway of SO 3 2− and generation pathway of relevant ROS were proposed.

Protein Encapsulated Covellite CuS Nanospheres for the Efficient Oxidative Degradation of Organic Dyes in Wastewater

“…The second doublet binding energy states at 935.8 eV and 955 was attributed to Cu 2p3/2 and Cu 2P1/2 electronic states of Cu 2+ . The difference of ~ 20 eV between the two states was in good agreement with reported value 37. In…”

Photoresponsive CuS@polyaniline nanocomposites: An excellent synthetic bactericide against several multidrug-resistant pathogenic strains

“…The peak at 520 cm −1 corresponds to disulfide (S-S) bonds, while the peaks at 608 cm −1 and 787 cm −1 correspond to copper-sulfur (Cu-S) stretching modes, and asymmetric valence sulfurhydrogen (S-H) stretching vibrations, indicating the presence of sulfur and metal sulfide bonds. 61,62 Additionally, the peaks appearing at 868, 1121, and 1235 cm −1 correspond to the carbon-hydrogen bond (C-H), carbon-nitrogen double bond (CvN), and carbon-nitrogen single bond (C-N) in aromatic structures, respectively, indicating the presence of aromatic groups. [62][63][64] These vibrational peaks provide clear evidence for the presence of disulfide, metal sulfide, and aromatic groups in the analyzed sample.…”

“…61,62 Additionally, the peaks appearing at 868, 1121, and 1235 cm −1 correspond to the carbon-hydrogen bond (C-H), carbon-nitrogen double bond (CvN), and carbon-nitrogen single bond (C-N) in aromatic structures, respectively, indicating the presence of aromatic groups. [62][63][64] These vibrational peaks provide clear evidence for the presence of disulfide, metal sulfide, and aromatic groups in the analyzed sample. The vibration bands observed at 1647 cm −1 and 1690 cm −1 are assigned to the carbon-carbon (C-C) bond ring stretching modes, and oxygen-hydrogen bending (O-H) bonds, respectively.…”

“…The vibration bands observed at 1647 cm −1 and 1690 cm −1 are assigned to the carbon-carbon (C-C) bond ring stretching modes, and oxygen-hydrogen bending (O-H) bonds, respectively. 62,64 In addition, the bands located at 3000-3100 cm −1 can be ascribed to the stretching vibration of C-H and NH bonds of the PANI. 64 The spectrum of CuS@PANI clearly shows noticeable changes, indicating the effect of incorporating PANI on CuS NPs.…”

Understanding the role of transition metal single-atom electronic structure in oxysulfur radical-mediated oxidative degradation

“…However, difficulty in recovery, risk of potential secondary contamination, and a narrow operating pH range limit the large-scale application [ 12 ]. To solve these issues, TM-based heterogeneous catalysts, mainly including zero-valent iron [ 13 , 14 ], TM oxide [ 12 , 15 ], TM sulfide [ 16 ], and spinel ferrite [ 17 , 18 ], have been developed for sulfite activation. Nevertheless, it remains a challenge to enhance the catalytic activity of the reaction, improve atomic economy, and reduce metal leaching.…”