Photocatalyst for High‐Performance H₂ Production: Ga‐Doped Polymeric Carbon Nitride

Abstract

A photocatalyst system is generally comprises a catalyst and cocatalyst to achieve light absorption, electron‐hole separation, and surface reaction. It is a challenge to develop a single photocatalyst having all functions so as to lower the efficiency loss. Herein, the active GaN4 site is integrated into a polymeric carbon nitride (CN) photocatalyst (GCN), which displays an excellent H2 production rate of 9904 μmol h−1 g−1. It is 162 and 3.3 times higher than that of CN with the absence (61 μmol h−1 g−1) and presence (2981 μmol h−1 g−1), respectively, of 1.0 wt % Pt. Under light irradiation the electron is injected and stored at the GaN4 site, where the LUMO locates. The HOMO distributes on the aromatic ring resulting in spatial charge separation. Transient photovoltage discloses the electron‐storage capability of GCN. The negative GaN4 promotes proton adsorption in the excited state. The positive adsorption energy drives H2 desorption from GaN4 after passing the electron to the proton. This work opens up opportunities for exploring a novel catalyst for H2 production.

Donor Bandgap Engineering without Sacrificing the Reduction Ability of Photogenerated Electrons in Crystalline Carbon Nitride

“…The short lifetime τ 1 may be related to interband recombination, whereas the long lifetime τ 2 represents surface recombination. Compared with KCN, the τ 1 , τ 2 , and τ average , and the surface recombination part increases significantly in TKCN(0.2), indicating that more shallow carrier traps prolong carriers lifetime [45] …”

Construction and performance of a simple and efficient g-C3N4 photocatalytic hydrogen production system

“…25,28 The binding energy of Na 1s is lower than that of Na-O bond (ca.1072.6 eV), 26 which indicates that sodium ions are embedded into the framework of CN to form Na-N bond instead of Na-O bond, and the electron state is uniform. 15,16,28,30 There are four binding energies locate at ca. 284.6, 286.4, 287.9 and 288.7 eV from the C 1s spectra (Fig.…”

“…In order to improve the photocatalytic performance of CN, numerous methods including nanostructure design, elemental doping, and construction of heterojunctions with other semiconductor materials have been developed. [13][14][15][16][17][18][19] For example, Na, K, Co, Ga, Pt, Ag, B, F, P, and S atoms were introduced into the structure of CN by multiple step calcination [14][15][16][17][18][19][20][21][22] and enhanced photocatalytic activity were achieved. Among them, Na doping is a very popular strategy as it is cheap and easy to get, and without introduce any pollution.…”

Regulating Local Electron Density of Iron Single Sites by Introducing Nitrogen Vacancies for Efficient Photo‐Fenton Process

“…[24] The electronic configuration of LUMO can almost represent the photogenerated electronic configuration. [25] Compared with the barely located electrons at Fe sites in Fe 1 /CN, the distribution of LUMO of Fe 1 -N v /CN reveals that more electrons are concentrated at the single Fe sites with ideal electronic configuration for H 2 O 2 activation.…”