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This paper considers the photoelectrochemical characteristics of a composite porous TiO2 thin film with deposited plasmonic gold nanoparticles. The deposition of gold nanoparticles was carried out by the laser-induced chemical liquid-phase deposition (LCLD) method. The structural characteristics of the composite have been studied; it has been shown that the porous TiO2 film has a lattice related to the tetragonal system and is in the anatase phase. Gold nanoparticles form on the surface of a porous TiO2 film. A complex of photoelectrochemical measurements was carried out. It was shown that the deposition of plasmonic gold nanoparticles led to a significant increase in the photocurrent density by ~820%. The proposed concept is aimed at testing the method of forming a uniform layer of plasmonic gold nanoparticles on a porous TiO2 film, studying their photocatalytic properties for further scaling, and obtaining large area Au/TiO2/FTO photoelectrodes, including in the roll-to-roll process. [ABSTRACT FROM AUTHOR]

Novel photocatalysts for CO2 reduction, which consist of a cadmium and zinc sulfide solid solution (Cd1−xZnxS), were successfully prepared by a simple two-step technique. The photocatalysts were characterized by X-ray diffraction, UV-VIS diffuse reflectance spectroscopy, and low-temperature N2 adsorption techniques and were tested in the gas-phase photocatalytic reduction of CO2 under visible light (λ = 450 nm). All the synthesized Cd1−xZnxS solid solutions were capable of enabling the chemical transformations of CO2 under the conditions considered. Carbon monoxide was the major product during the CO2 reduction over Cd1−xZnxS (x = 0–0.87). Methane and hydrogen were also detected in the gas phase in low amounts. The activity of the prepared samples and the distribution of the reduction products strongly depended on the actual cadmium to zinc ratio. The Cd0.94Zn0.06S photocatalyst showed the highest activity, 2.9 μmol CO per gram per hour, and selectivity, 95%, during CO2 reduction under visible light in the presence of water vapor. The achieved values are very high for the sulfide-based photocatalysts. [ABSTRACT FROM AUTHOR]

Abstract: The photocatalytic properties of a Cd0.3Zn0.7S photocatalyst modified either by NiS doping or by supporting NiS on the catalyst surface were studied. The obtained samples were investigated by different characterization techniques, including X‐ray diffraction (XRD), UV/Vis diffuse reflectance spectroscopy (DRS), high‐resolution transmission electron microscopy (HRTEM), and X‐ray photoelectron spectroscopy (XPS). The photocatalytic activity was measured in hydrogen evolution from aqueous solutions of Na2S/Na2SO3 under visible‐light irradiation (λ=450 nm). Nickel modifications on the surface and in bulk led to improvements in the photocatalytic activity compared to the pristine sample. The samples modified in bulk underwent changes in composition and an increase of the catalytic activity during illumination was measured. In contrast, the rate of hydrogen photoproduction for the photocatalysts modified by NiS on the surface did not change appreciably. The highest photocatalytic activity values were 11.2 mmol h−1 g−1 and 12.8 mmol h−1 g−1 for the 0.3 % NiS/Cd0.3Zn0.7S and Ni0.001Cd0.3Zn0.7S1.001 photocatalysts, respectively. [ABSTRACT FROM AUTHOR]

Two types of photocatalysts, 1%Pt/Cd1−xZnxS/g-C3N4 (x = 0.2–0.3) and Cd1−xZnxS/1%Pt/g-C3N4 (x = 0.2–0.3), were synthesized by varying the deposition order of platinum, and a solid solution of cadmium and zinc sulfides onto the surface of g-C3N4. The characterization of photocatalysts showed that, for 1%Pt/Cd1−xZnxS/g-C3N4, small platinum particles were deposited onto a solid solution of cadmium and zinc sulfides; in the case of Cd1−xZnxS/1%Pt/g-C3N4, enlarged platinum clusters were located on the surface of graphitic carbon nitride. Based on the structure of the photocatalysts, we assumed that, in the first case, type II heterojunctions and, in the latter case, S-scheme heterojunctions were realized. The activity of the synthesized samples was tested in hydrogen evolution from triethanolamine (TEOA) basic solution under visible light (λ = 450 nm). A remarkable increase in hydrogen evolution rate compared to single-phase platinized 1%Pt/Cd1−xZnxS photocatalysts was observed only in the case of ternary photocatalysts with platinum located on the g-C3N4 surface, Cd1−xZnxS/1%Pt/g-C3N4. Thus, we proved using kinetic experiments and characterization techniques that, for composite photocatalysts based on Cd1−xZnxS and g-C3N4, the formation of the S-scheme mechanism is more favorable than that for type II heterojunction. The highest activity, 2.5 mmol H2 g−1 h−1, with an apparent quantum efficiency equal to 6.0% at a wavelength of 450 nm was achieved by sample 20% Cd0.8Zn0.2S/1% Pt/g-C3N4. [ABSTRACT FROM AUTHOR]

Ternary composite photocatalysts based on titania and solid solutions of CdS and ZnS were prepared and studied by a set of physicochemical methods including XRD, XPS, HRTEM, UV-vis spectroscopy, and electrochemical tests. Two synthetic techniques of platinization of Cd 1- x Zn x S/TiO 2 were compared. In the first case, platinum was deposited on the surface of synthesized Cd 1- x Zn x S ( x = 0.2-0.3)/TiO 2 P25; in the second one, Cd 1- x Zn x S ( x = 0.2-0.3) was deposited on the surface of Pt/TiO 2 P25. The photocatalytic properties of the obtained samples were compared in the hydrogen evolution from TEOA aqueous solution under visible light ( λ = 425 nm). The Cd 1- x Zn x S (10-50 wt%; x = 0.2-0.3)/Pt (1 wt%)/TiO 2 photocatalysts demonstrated much higher photocatalytic activity than the Pt (1 wt%)/Cd 1- x Zn x S (10-50 wt%; x = 0.2-0.3)/TiO 2 ones. It turned out that the arrangement of platinum nanoparticles precisely on the titanium dioxide surface in a composite photocatalyst makes it possible to achieve efficient charge separation according to the type II heterojunctions and, accordingly, a high rate of hydrogen formation. The highest photocatalytic activity was demonstrated by 20% Cd 0.8 Zn 0.2 S/1% Pt/TiO 2 in the amount of 26 mmol g -1 h -1 (apparent quantum efficiency was 7.7%) that exceeds recently published values for this class of photocatalysts., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Photocatalysts based on zinc hydroxide and a solid solution of CdS and ZnS were prepared via the precipitation method and used for photocatalytic hydrogen production from aqueous solutions of inorganic (Na 2 S/Na 2 SO 3 ) and organic (ethanol) sacrificial agents. The photocatalysts were tested in cyclic experiments for hydrogen evolution and studied using X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) techniques. Different transformations of the β-Zn(OH) 2 co-catalyst were observed in the presence of inorganic and organic sacrificial agents; namely, ZnS was formed in Na 2 S/Na 2 SO 3 solution, whereas the formation of ε-Zn(OH) 2 was detected in solution with ethanol. The composite Zn(OH) 2 /Cd 1- x Zn x S photocatalysts have great potential in various photocatalysis processes ( e.g. , hydrogen production, CO 2 reduction, and the oxidation of organic contaminants) under visible light., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Novel photocatalysts for CO2 reduction, which consist of a cadmium and zinc sulfide solid solution (Cd1-xZnxS), were successfully prepared by a simple two-step technique. The photocatalysts were characterized by X-ray diffraction, UV-VIS diffuse reflectance spectroscopy, and low-temperature N2 adsorption techniques and were tested in the gas-phase photocatalytic reduction of CO2 under visible light (λ = 450 nm). All the synthesized Cd1-xZnxS solid solutions were capable of enabling the chemical transformations of CO2 under the conditions considered. Carbon monoxide was the major product during the CO2 reduction over Cd1-xZnxS (x = 0-0.87). Methane and hydrogen were also detected in the gas phase in low amounts. The activity of the prepared samples and the distribution of the reduction products strongly depended on the actual cadmium to zinc ratio. The Cd0.94Zn0.06S photocatalyst showed the highest activity, 2.9 μmol CO per gram per hour, and selectivity, 95%, during CO2 reduction under visible light in the presence of water vapor. The achieved values are very high for the sulfide-based photocatalysts.