A General Strategy To Fabricate Ni_xP as Highly Efficient Cocatalyst via Photoreduction Deposition for Hydrogen Evolution

Abstract

Presently, precise deposition of transition metal phosphides at the electron outlet of photoactive materials as cocatalysts for hydrogen generation is rarely reported. Demonstrated here is a general photochemical strategy for the preparation of metal phosphides as cocatalysts for hydrogen generation. In this work, Ni x P was successfully deposited on g-C 3 N 4 using nickel sulfate (NiSO 4 ) and hypophosphite sodium (NaH 2 PO 2 ) as Ni and P sources, respectively. The Ni x P/g-C 3 N 4 composite exhibits excellent performance of hydrogen evolution via water splitting (about 8585 μmol g −1 h −1 in a triethanolamine aqueous solution under a 300 W Xe lamp with an AM 1.5G filter). More importantly, due to the intrinsic acid-resistant properties of Ni x P and g-C 3 N 4 , the Ni x P/g-C 3 N 4 composite demonstrated excellent acid-stable photocatalytic activity for H 2 evolution (stable run for 75 h under acidic solution of pH 2). Furthermore, the mechanism for photocatalytic activity of g-C 3 N 4 enhanced by Ni x P was investigated in detail by steady-state photoluminescence spectra and surface photovoltage spectra, which indicated that separation efficiency of photogenerated carriers from g-C 3 N 4 was effectively enhanced by Ni x P.

Rational Design and Fabrication of Noble‐metal‐free NixP Cocatalyst Embedded 3D N‐TiO2/g‐C3N4 Heterojunctions with Enhanced Photocatalytic Hydrogen Evolution

“…With further thermal treatment, crystallinity of N ‐TiO 2 and binding ability between them were improved . On the basis of photochemical deposition method, Ni x P particles were well‐distributed around the N ‐TiO 2 /CN heterostructure.…”

“…), metal phosphide (Ni x P, Co x P, MoP, Fe x P, etc. ) to replace the noble metals. Recently, metal phosphides, such as g‐C 3 N 4 /Co x P, g‐C 3 N 4 /Fe x P, g‐C 3 N 4 /Ni x P TiO 2 /CoP, and so on, have been considered to be proper non‐precious noble‐metal‐free catalysts for catalytic hydrogen production through water splitting.…”

“…) to replace the noble metals. Recently, metal phosphides, such as g‐C 3 N 4 /Co x P, g‐C 3 N 4 /Fe x P, g‐C 3 N 4 /Ni x P TiO 2 /CoP, and so on, have been considered to be proper non‐precious noble‐metal‐free catalysts for catalytic hydrogen production through water splitting. Although metal phosphide has been used as the co‐catalysts in TiO 2 or g‐C 3 N 4 nanomaterials, to our best knowledge, no previous study regarding the application of metal phosphide on TiO 2 /g‐C 3 N 4 heterostructure.…”

“…Moreover, if the metal phosphide is obtained by the phosphorization on the surface of TiO 2 /g‐C 3 N 4 , TiO 2 may be doped by phosphorus element . On the other hand, the distribution of metal phosphide maybe a headache, physical mixing will not make metal phosphide uniformly dispersed on the surface of TiO 2 and g‐C 3 N 4 , resulting in a great influence on the electron transfer . Thus, the application of metal phosphide as co‐catalysts on TiO 2 /g‐C 3 N 4 heterostructure remains very challenging.…”

Highly Dispersed and Small‐Sized Nickel(II) Hydroxide Co‐Catalyst Prepared by Photodeposition for Hydrogen Production

“…Photo-deposition is am ild, novel and efficient methodf or synthesizing co-catalysts. In the previousr esearch of our group,t he photo-deposition method was used to deposit transition metal sulphides, [37,38] transition metal phosphide, [39,40] and transition metal element. [41,42] Nevertheless, the size of cocatalystw as large uncontrollable.…”