Phosphate-modified graphitic C3N4 as efficient photocatalyst for degrading colorless pollutants by promoting O2 adsorption

Abstract

The photocatalytic activity for degrading gas-phase acetaldehyde and liquid-phase phenol by graphitic carbon nitride could be greatly improved after modification with phosphoric acid, which is attributed to the clear increase in adsorbed O2 which prolongs the lifetime and enhances the separation of photogenerated charge carriers. This is based on O2 temperature-programmed desorption curves, steady-state surface photovoltage spectra, and time-resolved surface photovoltage responses.

Peroxymonosulfate enhanced visible light photocatalytic degradation bisphenol A by single-atom dispersed Ag mesoporous g-C3N4 hybrid

“…Graphitic carbon nitride (g-C 3 N 4 ), as a metal-free polymeric semiconductor, has shown huge potential in the field of photocatalytic H 2 evolution [1][2][3], CO 2 reduction [4,5], contamination elimination [6,7], and H 2 O 2 synthesis [8][9][10]. With an optical band gap of 2.70 eV, g-C 3 N 4 has shown a response to visible light up to 460 nm.…”

Enhanced photo-induced charge separation and sun light-driven photocatalytic performance of g-C3N4 modified by phosphate

“…It is plausible that the g-C 3 N 4 active sites will be covered by NH 4 H 2 PO 4 ; therefore, it is unfavorable for charge transport and the SPS response decreases [6]. The results in our case are not the same as the results reported by Jing et al They prepared phosphatemodified graphitic C 3 N 4 by a general immersion process in different-content phosphoric acid (or other inorganic acids) solutions, followed by thermal treatment at 723 K for 1 h [6]. The samples exhibit no SPS response from 425 to 500 nm, the difference may due to the treatment temperature and precursor of C 3 N 4 .…”

“…Continuous efforts have been devoted to enhance photocatalytic activity of g-C 3 N 4 . Among these approaches, modification of g-C 3 N 4 by acid is an effective and simple way [5,6]. However, the effects of phosphate on the preparation, the separation of photo-generated charge in visible light region, and sun light-driven photocatalytic performance of g-C 3 N 4 have been seldom addressed.…”

Covalent combination of polyoxometalate and graphitic carbon nitride for light-driven hydrogen peroxide production

“…In contrast, 3DOM g-C 3 N 4 -PW 11 exhibits n=2.30, indicating the covalent combination of 3DOM g-C 3 N 4 and PW 11 can selectively promote the two-electron O 2 reduction. It has been reported that the enhanced O 2 adsorption of catalysts can promote the multi-electron reduction of O 2 [36,38]. Furthermore, O 2 temperature programmed desorption (O 2 -TPD) has been performed to detect the changes of oxygen species after the covalent combination (Fig.…”