Electron Configuration Modulation of Nickel Single Atoms for Elevated Photocatalytic Hydrogen Evolution

Abstract

The emerging metal single‐atom catalyst has aroused extensive attention in multiple fields, such as clean energy, environmental protection, and biomedicine. Unfortunately, though it has been shown to be highly active, the origins of the activity of the single‐atom sites remain unrevealed to date owing to the lack of deep insight on electronic level. Now, partially oxidized Ni single‐atom sites were constructed in polymeric carbon nitride (CN), which elevates the photocatalytic performance by over 30‐fold. The 3d orbital of the partially oxidized Ni single‐atom sites is filled with unpaired d‐electrons, which are ready to be excited under irradiation. Such an electron configuration results in elevated light response, conductivity, charge separation, and mobility of the photocatalyst concurrently, thus largely augmenting the photocatalytic performance.

Recent Progress in Single‐Atom Catalysts for Photocatalytic Water Splitting

“…Additionally, Shi and coworkers successfully fabricated atomically dispersed Ni-based catalysts by a freezing deposition approach, which can effectively facilitate hydrogen evolution in photocatalytic water splitting. [112] From the high-angle annular dark-field STEM (HAADF-STEM) image, isolated Ni was atomically stabilized in the framework of polymeric carbon nitride, where one Ni atom was coordinated with four N atoms and one C atom, as revealed by DFT calculations. It has been proven that this synthesis approach can help realize the high dispersion of isolated Ni and would guarantee the atomic-scale control of single metal atoms during the synthesis of SACs.…”

“…dispersed Ni in polymeric carbon nitride (CN) through freezing deposition, which can effectively catalyze water splitting into hydrogen under light illumination. [112] In the synthesis procedure, CN was ultrasonicated in Reproduced with permission. [179] Copyright 2019, Elsevier.…”

“…When Al loading reached 0.32 wt%, the resultant Al-aa(0.32%)_PCN photocatalyst exhibited superior performance Reproduced with permission. [112] Copyright 2020, Wiley.…”

Highly Efficient and Selective CO2Electro‐Reduction to HCOOH on Sn Particle‐Decorated Polymeric Carbon Nitride

“…location to form MÀ CN composites for CO 2 RR and oxygen reduction/ evolution reaction. [10,12,13] Motivated by these studies, we here developed a Sn/CN catalyst via a facile approach, reducing Sn 2 + by NaBH 4 in the presence of CN. As we expected, the Sn species and the CN matrix were strongly bound via chemical bonds, making the composite catalyst a stable structure.…”

Silver Single Atom in Carbon Nitride Catalyst for Highly Efficient Photocatalytic Hydrogen Evolution

“…[9] Furthermore, the excited electrons of CN are mainly distributed in the C atoms because the C atoms chiefly contribute to the bottom of conduction band (CB). [10] As a result, the excited electrons of CN in the CB need to overcome a high energy barrier to transfer to metal atoms when the SACs have M-N x coordination. Especially, if SACs are fabricated using metals with low work functions in CN, it becomes difficult for the SAC to transfer its excited electrons from CN to metal atoms with M-N x coordination, leading to poor catalytic activity.…”