Novel synthesis of nickel oxide microsphere with high surface area and its catalytic application for carbon dioxide reforming of methane

Nickel oxide(NiO)microsphere with a large surface area was novelly synthesized through nickel bicarbonate(Ni(HCO3)2)precursor.The obtained nickel oxide(NiO)microsphere was characterized by X-ray pattern diffraction,scanning electron microscopy,CO2 temperature-programmed desorption,H2 temperature-programmed reduction,N2 adsorption/desorption and laser scattering particle size distribution analyzer.It was found that nickel oxide(NiO)synthesized by the thermal decomposition of Ni(HCO3)2through area hydrolysis,presented very nice microsphere with high surface area.The catalytic properties of obtained nickel oxide(NiO)microsphere were studied in the reaction of carbon dioxide reforming of methane where 91.3% conversion of CH4 with 93% conversion of CO2 was observed.Besides,the catalyst maintained high stability over 200 h on the stream.

Developing hierarchical CdS/NiO hollow heterogeneous architectures for boosting photocatalytic hydrogen generation

The hierarchical binary CdS/NiO hollow heterogeneous architectures(HHAs)with p–n heterojunction are constructed by a facile microwave-assisted wet chemical process for high-efficient photocatalytic hydrogen evolution reaction(HER)from water.The as-designed CdS/NiO HHAs are composed of hexagonal n-type CdS nanoparticles with a size in the range of 20–40 nm attaching to cubic p-type NiO hollow microspheres(HMSs)which are aggregates of porous nanoplates with a thickness of about 20 nm.The photocatalytic water splitting over CdS/NiO HHAs is significantly increased under simulated solar irradiation,among which the most active sample of CdS/NiO-3(the mass ratio of CdS to NiO is 1:3)exhibits the fastest photocatalytic HER rate of 1.77 mmol∙g^(−1)∙h^(−1),being 16.2 times than that of pure CdS.The boosted photocatalytic HER could be attributed to the synergistic effect on the proportional p–n heterojunction with special hierarchical hollow and porous morphology,an enhancement of visible light absorption,and an improvement of photoinduced charge separation as well as the photo-stability given by the composite heterojunction.This work shows a viable strategy to design the heterojunction with special morphology for the efficient hydrogen generation by water splitting utilizing solar energy.