Single-step synthesis and catalytic activity of structure-controlled nickel sulfide nanoparticles

Abstract

Nanoparticle single-phase nickel sulfides such as NiS, NiS 2 , Ni 3 S 4 , and Ni 7 S 6 were prepared from elemental sulfur and nickel nitrate hexahydrate, using a temperature-controlled precursor injection method. The initial ratio of the concentrations of the sources was used to control the size and phase of the final product.Phase control was confirmed using X-ray diffraction and transmission electron microscopy. The synthesized nickel sulfide phases, which had metallic characteristics, were used to study the catalytic reduction of 4-nitrophenol. The results showed that the catalytic activity of the NiS nanoparticles in the reduction of 4-nitrophenol to 4-aminophenol was higher than those of the other nickel sulfide phases. In addition, the nanocrystals showed good separation ability and reusability for reduction of 4-nitrophenol.

In situ Growth of Phase‐Controlled Nickel Sulfide Nanostructures on Reduced Graphene Oxide Nanosheets : A Improved Cost‐effective Catalyst for 4‐Nitrophenol Reduction

“…Adding rGO increased the reaction rate, which made monitoring the reaction progress with UV‐vis absorption spectrophotometry difficult. The concentration of NaBH 4 was reduced to 335 mg in 200 mL of water, to allow comparison of the current results with reported values . The ratio of 4‐nitrophenol to NaBH 4 was fixed as 2:3 in all the experiments.…”

“…We have investigated phase controlled nickel sulfide nanoparticles, with the aim of finding new catalysts with higher activities and reduction rates . There have been many reports of the synthesis of nickel sulfide/graphene oxide (GO) nanostructures for application in solar cells, lithium‐ion batteries, and supercapacitors .…”

“…We have investigated phase controlled nickel sulfide nanoparticles, with the aim of finding new catalysts with higher activities and reduction rates. [21] There have been many reports of the synthesis of nickel sulfide/graphene oxide (GO) nanostructures for application in solar cells, [22] lithium-ion batteries, [23][24][25] and supercapacitors. [26][27][28][29][30][31] However, the usefulness of these syntheses are limited by difficulties in controlling the phase, and problems with graphene reduction.…”

A Z‐Scheme Strategy that Utilizes ZnIn2S4 and Hierarchical VS2 Microflowers with Improved Charge‐Carrier Dynamics for Superior Photoelectrochemical Water Oxidation

“…[30] The peaks within the range 400-700 cm À1 were assigned to metalÀsulfur bonds, [31] whilst the peaks at about 2921 and 2852 cm À1 were assigned to CÀHs tretching modes. [32,33] In the FTIR spectrum of VS 2 ,a part from the peaks mentioned above, ap eak was observed at 984 cm À1 , which was assigned to the n(V=S) terminal Sstretches, which confirmed the presence of the V 4+ + oxidation state in VS 2 . [34] AV =S peak was also observed in the spectrum of ZnIn 2 S 4 -VS 2 ,a lbeit slightly shifted towards higher energy compared to that in the VS 2 spectrum, which could be indicative of interactions between ZnIn 2 S 4 and the terminal Sa toms of VS 2 .T his observation was further investigated by using XPS analysis (see below).…”

“…The band at about 1620 cm −1 corresponded to O−H bending vibrations of adsorbed water molecules, whilst the band at about 1390 cm −1 was attributed to surface‐adsorbed hydroxy groups . The peaks within the range 400–700 cm −1 were assigned to metal−sulfur bonds, whilst the peaks at about 2921 and 2852 cm −1 were assigned to C−H stretching modes . In the FTIR spectrum of VS 2 , apart from the peaks mentioned above, a peak was observed at 984 cm −1 , which was assigned to the ν (V=S) terminal S stretches, which confirmed the presence of the V 4+ oxidation state in VS 2 .…”