Highly Efficient Simulated Solar Light‐Driven Photocatalytic Degradation of 4‐Nitrophenol over CdS/Carbon/MoS_x Hybrids

Abstract

Among the various organic pollutants and industrial chemicals, 4-nitrophenol has been one of the most monitored substances in aqueous environments, due to its enhanced solubility in such systems. This research reports for the first time the microwave-assisted synthesis of CdS/carbon/MoS x hybrids and the subsequent utilization of such systems as photocatalysts for 4-nitrophenol degradation. The hybrids demonstrated a variable photocatalytic activity, by using a variety of organic substances as precursors for the solvothermal carbonization step. By using ascorbic acid as precursor, the corresponding ternary composite exhibited excellent photocatalytic activity, with the 4-nitrophenol concentration been almost quantitatively decayed within 45 min of irradiation. This could be ascribed due to the generation of a high population of heterojunctions as well as the chemical speciation of Mo-based nanostructures. Such ternary hybrids may be utilized as potential photocatalytic systems in processes, where removal of toxic water-soluble substances is the key issue.

Construction of Pd‐Co‐Doped CdS Heterojunctions as Efficient Platforms in Photocatalysis

“…The absorption edge of neat CdS nanoparticles was found to appear at about 548 nm (Figure 5a). [33] In sharp contrast, a representative ternary hybrid, such as CdS in situ @Pd 90 CoO 10 , exhibited an absorption spectrum which was found to be shifted by about 90 nm (Figure 5a).…”

“…Thus, the band gap of the abovementioned ternary hybrid was calculated to be 1.93 eV. It is noted that the band gap of undoped CdS nanoparticles was estimated to be 2.26 eV [33] . The band gap decrease in the doped semiconductors may be ascribed to the formation of optically active sub‐levels [34] …”

Bifunctional Nanostructured Palladium/MoSx Electrocatalyst for Cathode Hydrogen Evolution Reaction PEM Water Electrolysis and Oxygen Reduction Reaction

“…The former component was ascribed to MoS x species with Mo oxidation state +5. [ 50 ] An alternative assignment could be molybdenum oxysulfide species (MoS x O y ) with similar Mo oxidation state. [ 51 ] The higher‐binding‐energy component at 232.3 eV was attributed to Mo(VI) species.…”

Sulfonylation reactions photocatalyzed by quantum dots: rule of band-position and surface chemistry

“…20 Other examples involving QDs as catalysts can also be cited, such as photocatalytic hydrogen generation, 21 and photodegradation of dyes, and 4-nitrophenol. 22,23 The electron relative potentials of the valence and conduction bands allow the specific design of nanoparticles, which can be applied on oxidation and reduction processes. For instance, under visible light, the 3-mercaptopropionic acid (MPA) capped NiCl 2 /CdSe system was used to oxidize alcohols to aldehydes and ketones without any additional oxidant, using water as solvent.…”

“…20 Other examples involving QDs as catalysts can also be cited, such as photocatalytic hydrogen generation, 21 and photodegradation of dyes, and 4-nitrophenol. 22,23…”