| With the rapid development of scientific research,the exploration of semiconductor based photocatalytic functional materials with multifunctional applications has attracted great attention.The utilization of solar energy for hydrogen generation and photodegradation of organic pollutants in aqueous solution has aroused widespread concern in the field of environmental protection.Numerous materials including noble metals and metal oxides,semiconductors,as well as their integrations have been explored as promising photocatalysts in solving the energy crisis and environmental pollution problems.Nevertheless,developing novel photocatalysts with high solar energy utilization and environmental friendless characteristics are still of great significance in order to put them into practical applications.Various technologies involving versatile doping process,modulation of crystal morphology or the crystal facet control,and constructions of heterojunctions have been applied for rational design of novel photocatalysts with improved catalytic performance.Morphology modulation of photocatalyst has been demonstrated to be a crucial strategy for improving their catalytic performance in solar energy conversion system.Here,we systematically investigated the influence of the solvent-dependent morphology evolution of Zn2GeO4 phase on the photocatalytic efficiency of g-C3N4/Zn2GeO4 composites.The morphologies of Zn2GeO4 were rationally tuned from flower-like nanosheets to length-controllable nanorods,and microclusters assembled from microrods through regulating the solution polarity from different organic solvents.Accordingly,the Zn2GeO4 sample prepared in ethylene glycol(EG)with long rod-like morphology and integrated with g-C3N4,abbreviated as g-C3N4/Zn2GeO4(1:1)-EG,exhibited the best visible-light absorption ability and the highest efficiency.The synergetic effect of the long rod-like Zn2GeO4 phase with more exposed(110)crystalline facets and g-C3N4 accelerates the separation and interface transportation of photoexcited charge carriers,as confirmed by means of photocurrent measurements.The MB degradation mechanism was proposed to clarify the charge transfer process and the improved photodegradation activity.This study offers an experimental basis for understanding the significance of morphology control on rational design photocatalysts.Micro/nanostructural semiconductors have been proven to have great potential as photocatalysts in the field of catalysis.Here,hierarchical ZnxCd1-xS(x-1,0.85,0.74,0.64,0.46,and 0.36)microclusters were successfully prepared through a secondary growth strategy using ethanol as solvent under solvothermal condition.The cluster-like ZIF-8 crystals derived from crystalline hierarchical zin carbonate,CdCl2 inorganic salt and thiourea with stoichiometric ratios were used as the starting materials.The as-prepared hierarchical hierarchical Zn0.64Cd0.36S composite exhibits excellent water splitting performance with maximum H2 generation rate of 815 μmol/g/h under visible-light irradiation in the presence of sacrificial agent of 0.25 M Na2S and 0.35 M Na2SO3.The hydrogen generation efficiency is of about 23 times higher than that of pure CdS(34.7 μmol/g/h)and 14 times of the Zn0.64Cd0.36S reference(56.41μmol/g/h)obtained though one-pot hydrothermal method.The synergetic effect of Zn0.64Cd0.36S as photocatalyst for enhanced hydrogen generation and the corresponding photocatalytic mechanism involved were discussed in detail.This work demonstrates a feasible morphology preserved strategy to prepare novel hierarchical composites with specific chemical composition,high surface area,abundant active sites,as well as rapid diffusion and separation of photogenerated charge carriers for visible-light driven photocatalytic hydrogen generation. |
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