Phosphorylated g-C3N4/sulfur self-doped g-C3N4 homojunction carboxymethyl cellulose beads: An efficient photocatalyst for H2O2 production

Akash Balakrishnan; K Vijaya Suryaa; Hritankhi Tripathy; Suverna Trivedi; Arvind Kumar; Mahendra Chinthala

doi:10.1016/j.jcis.2024.02.110

Phosphorylated g-C₃N₄/sulfur self-doped g-C₃N₄ homojunction carboxymethyl cellulose beads: An efficient photocatalyst for H₂O₂ production

J Colloid Interface Sci. 2024 Jun:663:1087-1098. doi: 10.1016/j.jcis.2024.02.110. Epub 2024 Feb 22.

Authors

Akash Balakrishnan¹, K Vijaya Suryaa¹, Hritankhi Tripathy², Suverna Trivedi³, Arvind Kumar², Mahendra Chinthala⁴

Affiliations

¹ Process Intensification Laboratory, Department of Chemical Engineering, National Institute of Technology Rourkela, Odisha 769 008, India.
² Environmental Pollution Abatement Laboratory, Department of Chemical Engineering, National Institute of Technology Rourkela, Odisha 769 008, India.
³ Department of Chemical Engineering, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
⁴ Process Intensification Laboratory, Department of Chemical Engineering, National Institute of Technology Rourkela, Odisha 769 008, India. Electronic address: chinthalam@nitrkl.ac.in.

PMID: 38402009
DOI: 10.1016/j.jcis.2024.02.110

Abstract

The development of highly reusable, affordable, and durable photocatalysts for the production of hydrogen peroxide (H₂O₂) remained a challenge. In this study, a homojunction photocatalyst (SPGCN) is constructed between phosphorylated g-C₃N₄ (PCN) and sulfur self-doped g-C₃N₄ (SCN) using a simple wet impregnation method. Later, the obtained SPGCN homojunction is transformed into hydrogel beads using carboxymethyl cellulose via an effective cross-linking strategy (SPGCN/CMC). The photocatalytic beads displayed a phenomenal H₂O₂ production of 3.5 mM under visible light illumination for 60 min. The SPGCN/CMC hydrogel beads showed a maximum reusability of 10 cycles with a decline of 1.5 mM H₂O₂ production. The improved photocatalytic efficiency is indicated by strengthened utilization of visible light via tuning of the band gap, suppressed recombination of electron-hole pairs, and higher separation efficiency through the effective construction of Z-scheme between the phosphorylated carbon nitride and the sulfur-self-doped carbon nitride present in the SPGCN/CMC beads. The mechanistic studies affirmed the dominant role of superoxide radicals in H₂O₂ production. The photocatalytic H₂O₂ production followed a highly selective two-electron reduction reaction. Overall, this study highlights the efficient engineering of carbon nitride-based materials towards artificial photosynthesis.

Keywords: Carbon nitride; Cellulose; Hydrogen peroxide; Photocatalysis; Visible light.