Preparation of CdS–TiO₂-Based Palladium Heterogeneous Nanocatalyst by Solvothermal Route and Its Catalytic Activity for Reduction of Nitroaromatic Compounds

Abstract

In this study, bare CdS nanoparticles (NPs) were prepared by solvothermal method using CdCl2(3-methylbenzaldehyde thiosemicarbazone)2 as a single-source molecular precursor in the presence of ethylene glycol. Further, these CdS NPs were used for the preparation of binary (CdS–TiO2) and ternary (CdS–TiO2/Pd) heterogeneous nanocatalysts. Characterization of the as-prepared nanocatalysts has been carried out using different techniques such as powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV–visible diffuse reflectance spectroscopy, and photoluminescence studies. The peak observed at 2θ = 39.5° in XRD confirms the successful doping of noble metal (Pd) on the surface of CdS–TiO2 nanocatalyst, which is well supported by Raman analysis. From FESEM and TEM analyses, mixed morphology has been observed and elemental composition was confirmed by energy-dispersive X-ray spectroscopy elemental mapping. Furthermore, the as-prepared bare CdS NPs, binary CdS–TiO2, and ternary CdS–TiO2/Pd heterogeneous nanocatalysts were used for the reductive transformation of various nitroaromatic compounds to their corresponding aromatic amines at room temperature. It has been observed that among all of the catalysts, ternary CdS–TiO2/Pd heterogeneous nanocatalyst has excellent catalytic property to reduce all nitroaromatic compounds in very short time span.

CdS Q-Dot-Impregnated TiO2-B Nanowire-Based Photoanodes for Efficient Photovoltaic Conversion in ‘Q-Dot Co-sensitized DSSC’

“…The wet impregnation process was adopted for the preparation of the CdS Qdot-sensitized TiO 2 -B NW composite. 71 In the synthesis of 5 wt % CdS in the TiO 2 -B composite, 1 g of the prepared TiO 2 -B NWs was well dispersed in 60 mL of deionized water by magnetic stirring for 45 min to obtain a homogenous solution at room temperature. Subsequently, 25 mL of a 0.012 M Cd(NO 3 ) 2 •4H 2 O aqueous solution was added drop by drop for 1.5 h under fixed magnetic stirring.…”

Recent applications of nanoparticles in organic transformations

“…The one-pot solvothermal route for the synthesis of Pd nanoparticles has been explained by many researchers. 25 A strategy adopted by the Domingos group was based on the in situ growth of Pd nanoparticles on the surface of magnetite (Scheme 9a). 26 Magnetite particles were coated with the natural polymer dextran and further modified by Pd nanoparticles on their surface (Fe 3 O 4 @dextran/Pd) 32 .…”

Surfactant-free synthesis of Ag@TiO2 and CuO@TiO2 photocatalyst: a comparative study of their photocatalytic activity for reduction of nitroaromatics in water

“…The semiconductor-based photocatalysts have immerged as fascinating candidates due to their heterogeneous nature, adaptability to holding multiple oxidation states, lower band gap, and eco-friendliness. For the reduction of nitroaromatic compounds various reports are available utilizing noble and non-noble metal-based transition metal oxides semiconductors including Cu 2 O/TiO 2 , CuCo 2 O 4 /RGO, Au/TiO 2 , Pd/ZnO, Cu/Ag-ZnO, Fe 3 O 4 @Cu, Au/Fe 3 O 4 and so forth [18][19][20][21]. TiO 2 is one of the most widely used high-performance photocatalysts with a band gap of 3.2-3.4 eV [22].…”