Heterostructure Construction of Noble-metal-free TernaryComposite Ni(PO3 2-Ni2P/CdS NPs and Its Visible LightEfficient Catalytic Hydrogen Production br

The development of visible-light-driven efficient???stable???and inexpensive photocatalysts for water-splitting hydrogen production is an important topic to address global energy and environmental challenges.In thiswork???a highly efficient???stable???and non-noble metal CdS-based photocatalytic composite Ni???PO3???2-Ni2P/CdS NPswas synthesized by combining cocatalyst modification and heterostructure construction strategy.Binary cocatalystNi???PO3???2-Ni2P nanosheet arrays were prepared using flower bulb Ni???OH???2as precursor by gas-phase sinteringphosphating process???and CdS NPs were combined with them to form a new type of ternary composite photocatalyst???Ni???PO3???2-Ni2P/CdS NPs???by sonochemical.The photocatalytic hydrogen production rate of8%???mass fraction???Ni???PO3???2-Ni2P/CdS NPs reaches4237 mu molmiddotg???1middoth???1with Na2S-Na2SO3as sacrificial agent under the irradiation ofvisible light???lambda>420nm??????which is about19times for CdS NPs???217 mu molmiddotg???1middoth???1???.In the cycling experiment???thehydrogen production rate of reaction is about89% of the initial value after sixth cycles???18h??????which demonstratesexcellent catalytic stability.Compared with CdS NPs???the absorption edge of Ni???PO3???2-Ni2P/CdS NPs is obviously red-shifted???the forbidden band width is reduced to1.86eV???and the overpotential of H+reduction is reduced???whichexhibits strong light absorption properties and a suitable band gap structure.The photogenerated electrons of CdS NPsare transferred to Ni???PO3???2-Ni2P through the synergistic effect between Ni???PO3???2-Ni2P and CdS NPs???which effective???ly promotes the separation of photogenerated carriers and improves the activity and stability of hydrogen production.This noble-metal-free composite photocatalyst may provide a way to design very efficient water splitting catalysts???which will promotes the practical industrial application of CdS visible photocatalytic water splitting