Cost-Effective and Highly Efficient Manganese-Doped MoS₂ Nanosheets as Visible-Light-Driven Photocatalysts for Wastewater Treatment

Abstract

One of the main objectives in wastewater treatment and sustainable energy production is to find photocatalysts that are favorably efficient and cost-effective. Transition-metal dichalcogenides (TMDs) are promising photocatalytic materials; out of all, MoS2 is extensively studied as a cocatalyst in the TMD library due to its exceptional photocatalytic activity for the degradation of organic dyes due to its distinctive morphology, adequate optical absorption, and rich active sites. However, sulfur ions on the active edges facilitate the catalytic activity of MoS2. On the basal planes, sulfur ions are catalytically inactive. Injecting metal atoms into the MoS2 lattice is a handy approach for triggering the surface of the basal planes and enriching catalytically active sites. Effective band gap engineering, sulfur edges, and improved optical absorption of Mn-doped MoS2 nanostructures are promising for improving their charge separation and photostimulated dye degradation activity. The percentage of dye degradation of MB under visible-light irradiations was found to be 89.87 and 100% for pristine and 20% Mn-doped MoS2 in 150 and 90 min, respectively. However, the degradation of MB dye was increased when the doping concentration in MoS2 increased from 5 to 20%. The kinetic study showed that the first-order kinetic model described the photodegradation mechanism well. After four cycles, the 20% Mn-doped MoS2 catalysts maintained comparable catalytic efficacy, indicating its excellent stability. The results demonstrated that the Mn-doped MoS2 nanostructures exhibit exceptional visible-light-driven photocatalytic activity and could perform well as a catalyst for industrial wastewater treatment.

Hydrazine-Assisted Synthesis, Structures, Photoelectricity, and Photocatalysis of Ternary Mercury–Tellurostannate Hybrids with Transition-Metal Complexes

“…In order to determine the reason for the high photocatalytic activities of the catalysts, the valence states of the surface metals of catalysts 1 and 3 before and after catalysis were studied by XPS analysis, and the results are presented in Figures , S18, and S19. In the Mn 2p XPS spectrum of the as-prepared sample 1 (Figure a), the peaks at 641.4 and 653.5 eV represent the binding energies of Mn 2p 3/2 and Mn 2p 1/2 , respectively . The satellite peak at 647.1 eV corresponds to the binding energy of Mn 2+ .…”

Kagome-like BiP3 Monolayer: An Emerging Quasi-Direct Auxetic Semiconductor Coupled with High Anisotropic Mobility toward Visible-Light-Driven Photoelectrocatalytic pH-Robust Overall Water-Splitting

“…25−28 However, for these conventional photoelectrocatalysts, their applications in practical photocatalysis are significantly limited due to the unfavorable recombinations of photogenerated carriers, the inadequate potentials for multiple proton−electron-pair-transfer steps in water oxidization, the undesirable carrier mobility, the low sunlight usage rate, or the poor stability. 29,30 Therefore, suitable photocatalysts for water splitting that are entirely driven by sunlight are still rare. Obviously, for 2D photoelectrocatalysts, an emerging mechanism of intrinsic vertical electric field induced by structural out-of-plane asymmetry has recently been suggested to change the bandedge positions' alignments, thereby breaking the traditional limitations.…”

“…This objective necessitates that carriers exhibit both strongly anisotropic transport in specific directions and a low recombination probability of photoexcited electrons and holes. Currently, single-layer graphitic carbon nitrides (g-C 3 N 4 ), phosphorene, semiconducting transition-metal chalcogenides, and transition-metal carbides/nitrides have been experimentally and theoretically verified as potential candidates for photocatalytic water-splitting applications. − However, for these conventional photoelectrocatalysts, their applications in practical photocatalysis are significantly limited due to the unfavorable recombinations of photogenerated carriers, the inadequate potentials for multiple proton–electron-pair-transfer steps in water oxidization, the undesirable carrier mobility, the low sunlight usage rate, or the poor stability. , Therefore, suitable photocatalysts for water splitting that are entirely driven by sunlight are still rare. Obviously, for 2D photoelectrocatalysts, an emerging mechanism of intrinsic vertical electric field induced by structural out-of-plane asymmetry has recently been suggested to change the band-edge positions' alignments, thereby breaking the traditional limitations. , …”

Improved Optical, Photocatalytic, Electrical, And Antimicrobial Properties of Tio2 Doped with Phosphomolybdic Acid Composites

“…TiO 2 -phosphomolybdic acid composite is a novel photocatalyst with enhanced photocatalytic activity (4), which, due to its unique structure. Its activity results from the presence of the two components, TiO 2 and phosphomolybdic acid.…”