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Hydrogen energy from solar water-splitting is known as an ideal method with which to address the energy crisis and global environmental pollution. Herein, the first-principles calculations are carried out to study the photocatalytic water-splitting performance of single-layer GaInSe3 under biaxial strains from −2% to +2%. Calculations reveal that single-layer GaInSe3 under various biaxial strains has electronic bandgaps ranging from 1.11 to 1.28 eV under biaxial strain from −2% to +2%, as well as a completely separated valence band maximum and conduction band minimum. Meanwhile, the appropriate band edges for water-splitting and visible optical absorption up to ~3 × 105 cm−1 are obtained under biaxial strains from −2% to 0%. More impressively, the solar conversion efficiency of single-layer GaInSe3 under biaxial strains from −2% to 0% reaches over 30%. The OER of unstrained single-layer GaInSe3 can proceed without co-catalysts. These demonstrate that single-layer GaInSe3 is a viable material for solar water-splitting. [ABSTRACT FROM AUTHOR]

Three ZnAl2O4 samples were prepared via a modified polyacrylamide gel method using a citric acid solution with different aluminum salt starting materials, including AlCl3∙6H2O, Al2(SO4)3∙18H2O, and Al(NO3)3∙9H2O under identical conditions. The influence of different aluminum salts on the morphologies, phase purity, and optical and fluorescence properties of the as-prepared ZnAl2O4 nanoparticles were studied. The experimental results demonstrate that the phase purity, particle size, morphology, and optical and fluorescence properties of ZnAl2O4 nanoparticles can be manipulated by the use of different aluminum salts as starting materials. The energy bandgap (Eg) values of ZnAl2O4 nanoparticles increase with a decrease in particle size. The fluorescence spectra show that a major blue emission band around 400 nm and two weaker side bands located at 410 and 445 nm are observed when the excitation wavelength is 325 nm. The ZnAl2O4 nanoparticles prepared from Al(NO3)3∙9H2O exhibit the largest emission intensity among the three ZnAl2O4 samples, followed in turn by the ZnAl2O4 nanoparticles prepared from Al2(SO4)3∙18H2O and AlCl3∙6H2O. These differences are attributed to combinational changes in Eg and the defect types of the ZnAl2O4 nanoparticles. [ABSTRACT FROM AUTHOR]

Three kinds of Al-TiO 2 samples and pure TiO 2 samples were synthesized via a modified polyacrylamide gel route using different aluminum salts, including Al 2 (SO 4 ) 3 ∙18H 2 O, AlCl 3 , and Al(NO 3 ) 3 ∙9H 2 O under identical conditions. The influence of different aluminum salts on the phase purity, morphologies, thermal stability of anatase and photocatalytic properties of the as-prepared Al-TiO 2 nanoparticles were studied. The energy gap (Eg) of Al-TiO 2 nanoparticles decreases due to Al ion doping into TiO 2 . The photocatalytic activities of the Al-TiO 2 samples were investigated by the degradation of acid orange 7 dye in aqueous solution under simulated solar irradiation. The Al-TiO 2 nanoparticles prepared from Al(NO 3 ) 3 ∙9H 2 O exhibit the best photocatalytic activity among the four kinds of samples, followed in turn by the Al-TiO 2 nanoparticles prepared with AlCl 3 , Al 2 (SO 4 ) 3 ∙18H 2 O and pure TiO 2 . The different performances are attributed to complex effects of Eg, particle size, surface morphology, phase purity and the defect sites of the Al-TiO 2 nanoparticles.