The controlled NiO nanoparticles for dynamic ion exchange formation of unique NiS/CdS composite for efficient photocatalytic H2 production

Photocatalytic reaction of water is one way to achieve clean hydrogen energy and high-efficient photocatalysts are essential. A facile and controlled syntheses of NiS/CdS photocatalysts by tuning nickel precursors are presented for improving photocatalytic performance. Ni-containing nanoparticles were prepared from the calcination of nickel salt. Better than Ni and Ni/NiO (unable to transform to NiS completely), NiO nanoparticles serve as nickel precursor to construct NiS via ion exchange process and the tight heterojunctions between NiS and CdS are achieved. The formed NiS/CdS composite exhibits excellent photocatalytic performance for hydrogen production under visible-light irradiation, better than normal NiS/CdS photocatalyst from soluble nickel salt precursor. The present NiO precursor as template with high surface area provides contact sites for CdS and the dynamic formation of NiS, which is conductive to improving crystallinity of NiS and adjusting the heterostructures between NiS and CdS. Various characterizations verify the superiority of the controlled NiS/CdS heterostructures, including the improved light absorption, photoelectrochemical performances and photocatalytic stability. An effective way is provided to enhance photocatalytic activity of metallic sulfide photocatalysts through the regulating of nanoparticles precursors for cocatalysts.