An electron-hole rich dual-site nickel catalyst for efficient photocatalytic overall water splitting

• Published in: Nature communications Vol. 14; no. 1; p. 1741
• Main Authors: Yan, Xiaoqing, Xia, Mengyang, Liu, Hanxuan, Zhang, Bin, Chang, Chunran, Wang, Lianzhou, Yang, Guidong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29-03-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/299/890; 639/4077/909/4086/4087; 639/638/439/890; 639/638/77/890; Catalysts; Density functional theory; Holes (electron deficiencies); Humanities and Social Sciences; Hybridization; Hydrogen; Hydrogen peroxide; Hydrogen production; Metal sulfides; multidisciplinary; Nickel; Nickel sulfide; Noble metals; Oxygen; Phosphides; Photocatalysis; Photocatalysts; Reagents; Science; Science (multidisciplinary); Splitting; Transition metal oxides; Water splitting
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-37358-3

Photocatalysis offers an attractive strategy to upgrade H
2
O to renewable fuel H
2
. However, current photocatalytic hydrogen production technology often relies on additional sacrificial agents and noble metal cocatalysts, and there are limited photocatalysts possessing overall water splitting performance on their own. Here, we successfully construct an efficient catalytic system to realize overall water splitting, where hole-rich nickel phosphides (Ni
2
P) with polymeric carbon-oxygen semiconductor (PCOS) is the site for oxygen generation and electron-rich Ni
2
P with nickel sulfide (NiS) serves as the other site for producing H
2
. The electron-hole rich Ni
2
P based photocatalyst exhibits fast kinetics and a low thermodynamic energy barrier for overall water splitting with stoichiometric 2:1 hydrogen to oxygen ratio (150.7 μmol h
−1
H
2
and 70.2 μmol h
−1
O
2
produced per 100 mg photocatalyst) in a neutral solution. Density functional theory calculations show that the co-loading in Ni
2
P and its hybridization with PCOS or NiS can effectively regulate the electronic structures of the surface active sites, alter the reaction pathway, reduce the reaction energy barrier, boost the overall water splitting activity. In comparison with reported literatures, such photocatalyst represents the excellent performance among all reported transition-metal oxides and/or transition-metal sulfides and is even superior to noble metal catalyst.
Vast majority of photocatalysts for hydrogen production relies on additional sacrificial agents and noble metal cocatalysts. It is of great importance yet challenging to achieve photocatalytic overall water splitting with decent performance. Here, the authors report Ni
2
P based photocatalyst assisted by H
2
O
2
-craking reaction for overall water splitting with H
2
and O
2
production of 1507 μmol h
−1
 g
−1
H
2
and 702 μmol h
−1
 g
−1
.