Graphitic C₃N₄ Decorated with CoP Co‐catalyst: Enhanced and Stable Photocatalytic H₂ Evolution Activity from Water under Visible‐light Irradiation

Abstract

In this work, graphitic C N decorated with a CoP co-catalyst (g-C N /CoP) is reported for photocatalytic H evolution reaction based on two-step hydrothermal and phosphidation method. The structure of g-C N /CoP is well confirmed by XRD, FTIR, TEM, XPS, and UV/Vis diffuse reflection spectra techniques. When the weight percentage of CoP loading is 3.4 wt % (g-C N /CoP-3.4 %), the highest H evolution amount of 8.4×10 μmol g is obtained, which is 1.1×10 times than that over pure g-C N . This value also is comparable with that of g-C N loaded by the same amount of Pt. In cycling experiments, g-C N /CoP-3.4 % shows a stable photocatalytic activity. In addition, g-C N /CoP-3.4 % is an efficient photocatalyst for H evolution under irradiation with natural solar light. Based on comparative photoluminescence emission spectra, photoelectrochemical I-t curves, EIS Nyquist plots, and polarization curves between g-C N /CoP-3.4 % and pure g-C N , it is concluded that the presence of the CoP co-catalyst accelerates the separation and transfer of photogenerated electrons of g-C N , thus resulting in improved photocatalytic activity in the H evolution reaction.

Atomic‐Level Insight into Optimizing the Hydrogen Evolution Pathway over a Co1‐N4 Single‐Site Photocatalyst

“…Meanwhile, the turnover frequency (TOF) of Co 1 /PCN (1.0 wt % Co loading; see the Supporting Information for the calculation) was calculated to be about 1.2 h −1 . Although our H 2 generation rate is not the best, the designed composite provides an ideal model to investigate the mechanism of enhanced H 2 evolution for the typical Co 1 ‐N 4 structure. Specifically, the Co 1 /PCN achieves a 3.02 % AQE at 450 nm, and 1.25 % at longer visible‐light wavelengths of 500 nm, which superior to the control samples.…”

Visible‐Light‐Driven Chemoselective Hydrogenation of Nitroarenes to Anilines in Water through Graphitic Carbon Nitride Metal‐Free Photocatalysis

“…[18] Since then, significant efforts have been made in g-C 3 N 4 -mediated photocatalysis, owing to its superior characteristics of appropriate visible-light response;t hermal stabilityu pt o6 00 8C; chemical stability in acid, alkali, and organic solvents;h igh surfacea rea;l ow cost;a nd the conven-ience of tuning its properties. [18,19,[25][26][27] It has hence found various applicationsi ne nergy and environmental fields, especially in hydrogen evolution, [28] CO 2 reduction, [29] water and gas purification, [30] and organic synthesis. [15,31] Furthermore, as aheterogeneous catalyst, g-C 3 N 4 possesses multiple functionalities, such as basic sites, hydrogen-bonding motifs,a nd electronic properties.…”

Atomic‐Level Insight into Optimizing the Hydrogen Evolution Pathway over a Co1‐N4 Single‐Site Photocatalyst

“…As expected, the Co 1 /PCN showed the best H 2evolution ability among the control samples under both UV/ Vis( l ! Notably,t he H 2 -evolution rate of Co 1 /PCN remained at 9.1 mmol h À1 under visible light irradiation, strongly suggesting the high activity of Co 1 -N 4 site.M eanwhile,t he turnover frequency( TOF) of Co 1 /PCN (1.0 wt % Co loading;s ee the Supporting Information for the calculation) was calculated to be about 1.2 h À1 .A lthough our H 2 generation rate is not the best, [19,30] the designed composite provides an ideal model to investigate the mechanism of enhanced H 2 evolution for the typical Co 1 -N 4 structure. 420 nm) irradiation (Supporting Information, Figure S4), manifesting the efficient utilization of visible light.…”