Investigation of La-BiVO₄/g-C₃N₄ photocatalytic system for efficient removal of hazardous water contaminants

Abstract

The application of semiconductor photocatalysis powered by renewable energy sources for environmental remediation of emerging contaminants has gained significant research interest in recent years. Lanthanum-substituted bismuth vanadate (La-BiVO₄)/graphitic carbon nitride (g-C₃N₄) heterojunctions were synthesized for the photocatalytic degradation of emerging water contaminants. Significantly, La³⁺ substitution serves as a model system for exploring the broader concept of cationic substitutions on BiVO₄. By strategically replacing a portion of Bi(III) with various cations, we can potentially tailor the electronic structure of BiVO₄ for enhanced photocatalytic performance. Photoelectrochemical analysis confirmed rapid charge separation and reduced resistance, leading to effective contaminant degradation. The La-BiVO₄/g-C₃N₄ nanocomposite exhibited exceptional photocatalytic performance under simulated solar light irradiation (Xe-350W, AM 1.5 G), achieving 87.66% photooxidation of roxarsone within 150 min, surpassing g-C₃N₄, BiVO₄, LaVO₄, La-BiVO₄, BiVO₄/g-C₃N₄, and LaVO₄/g-C₃N₄ by factors of 1.94, 1.26, 2.25, 1.39, 1.13, and 2.51, respectively. Moreover, it demonstrated 99.61% degradation of Cr(VI) after 60 min, outperforming g-C₃N₄, BiVO₄, LaVO₄, La-BiVO₄, BiVO₄/g-C₃N₄, and LaVO₄/g-C₃N₄ by factors of 1.11, 1.81, 1.62, 1.67, 1.20, and 1.13, respectively. These findings underscore the superior photocatalytic efficacy of the La-BiVO₄/g-C₃N₄ nanocomposite. The efficient photocatalytic activity of La-BiVO₄/g-C₃N₄ type-II heterojunctions demonstrates its potential for real-world environmental remediation. This material offers a promising strategy for removing harmful water contaminants, thereby mitigating risks associated with water consumption.

Keywords:

• Cr(VI)
• environmental remediation
• g-C₃N₄
• La-BiVO₄
• photocatalysis
• roxarsone

Acknowledgments

All authors would like to thank the Precision Analysis Materials Research Center, National Taipei University of Technology for providing all necessary instrument facilities.

Author contributions

Sridharan Balu: conceptualization, methodology, validation, investigation, writing – original draft, and writing – review and editing. Harikrishnan Venkatesvaran: methodology, investigation, and formal analysis. Kuo-Wei Lan: validation, investigation, and formal analysis. Thomas C.-K. Yang: conceptualization, methodology, validation, resources, supervision, funding acquisition, and writing – review and editing.

Ethical approval

Not applicable.

Consent to participate

Not applicable.

Consent for publication

The final version of the manuscript has been reviewed and approved by all the authors.

Disclosure statement

The authors declare no competing interests.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1080/00986445.2024.2372736.

Additional information

Funding

This work was supported by the National Science and Technology Council, Taiwan (NSTC; Grant Nos. 110-2923-E-027-001-MY3; 110-2221-E-027-006-MY2).