Herein a rich, Se-nanoparticle modified Mo-W18O49 nanocomposite as efficient hydrogen evolution reaction catalyst is reported via hydrothermal synthesized process. In this work, Na2SeSO3 solution and selenium powder are used as Se precursor material. The structure and composition of the nanocomposites are characterized by X-ray diffraction (XRD), high-resolution field emission scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), EDX spectrum analysis and the corresponding element mapping. The improved electrochemical properties are studied by current density, and EIS analysis. The as-prepared Se modified Mo-W18O49 synthesized via Na2SeSO3 is investigated by FE-SEM analysis and found to exhibit spherical particles combined with nanosheets. This special morphology effectively improves the charge separation and transfer efficiency, resulting in enhanced photoelectric behavior compared with that of pure Mo-W18O49. The nanomaterial obtained via Na2SeSO3 solution demonstrates a high HER activity and low overpotential of -0.34 V, allowing it to deliver a current density of 10 mA cm2.

Herein, a series of g-C3N4 modified Bi2MoO6 nanocomposites using Bi2MoO6 and melamine as original materials are fabricated via sintering process. For presynthesis of Bi2MoO6 an ultrasonic-assisted hydrothermal technique is researched. The structure and composition of the nanocomposites are characterized by Raman spectroscopy, X-ray diffraction (XRD), and high-resolution field emission scanning electron microscopy (SEM). The improved photoelectrochemical properties are studied by photocurrent density, EIS, and amperometric i-t curve analysis. It is found that the structure of Bi2MoO6 nanoparticles remains intact, with good dispersion status. The as-prepared g-C3N4/Bi2MoO6 nanocomposites (BMC 5-9) are selected and investigated by SEM analysis, which inhibits special morphology consisting of Bi2MoO6 nanoparticles and some g-C3N4 nanosheets. The introduction of small sized g-C3N4 nanosheets in sample BMC 9 is effective to improve the charge separation and transfer efficiency, resulting in enhancing of the photoelectric behavior of Bi2MoO6. The improved photoelectronic behavior of g-C3N4/Bi2MoO6 may be attributed to enhanced charge separation efficiency, photocurrent stability, and fast electron transport pathways for some energy applications.

In this study, photocatalytic degradation of ammonia in petrochemical wastewater is investigated by solar light photocatalysis. Two-dimensional ultra-thin atomic layer structured MoS2 are synthesized via a simple hydrothermal method. We examine all prepared samples by means of physical techniques, such as SEM-EDX, HRTEM, FT-IR, BET, XRD, XPS, DRS and PL. And, we use fullerene modified MoS2 nanosheets to enhance the activity of photochemically generated oxygen (PGO) species. Surface area and pore volumes of the MoS2-fullerene samples significantly increase due to the existence of MoS2. And, PGO oxidation of MB, TBA and TMST, causing its concentration in aqueous solution to decrease, is confirmed by the results of PL. The generation of reactive oxygen species is detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and the PGO effect increase in the case with modified fullerene. The experimental results show that this heterogeneous catalyst has a degradation of 88.43% achieved through visible light irradiation. The product for the degradation of NH3 is identified as N2, but not NO2−or NO3−.

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified Ag2Se nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the Ag2Se-graphene (Ag2Se-G) samples showed catastrophic decrease due to deposition of Ag2Se. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with Ag2Se composites increased significantly due to a synergetic effect between graphene and the Ag2Se nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

SnS-TiO2 nanocomposites are synthesized using simple, cheap, and less toxic SnCl2 as the tin (II) precursor. The prepared nanoparticles are characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectra (DRS). The XRD and TEM results indicate that the prepared product has SnS nanoparticles and a grain diameter of 30 nm. The DRS demonstrate that SnS-TiO2 possesses the absorption profile across the entire visible light region. The generation of reactive oxygen species is detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and photocatalytic effect increase with the modified SnS. Excellent catalytic degradation of Texbrite BA-L (TBA) solution is observed using the SnS-TiO2 composites under visible light irradiation. It is proposed that both the strong visible light absorption and the multiple exciton excitations contribute to the high visible light photocatalytic activity.