Dual-defect-modified graphitic carbon nitride with boosted photocatalytic activity under visible light

Hideyuki Katsumata; Fumiya Higashi; Yuya Kobayashi; Ikki Tateishi; Mai Furukawa; Satoshi Kaneco

doi:10.1038/s41598-019-49949-6

Dual-defect-modified graphitic carbon nitride with boosted photocatalytic activity under visible light

Sci Rep. 2019 Oct 16;9(1):14873. doi: 10.1038/s41598-019-49949-6.

Authors

Hideyuki Katsumata¹, Fumiya Higashi², Yuya Kobayashi², Ikki Tateishi³, Mai Furukawa², Satoshi Kaneco^{2

3}

Affiliations

¹ Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie, 514-8507, Japan. hidek@chem.mie-u.ac.jp.
² Department of Chemistry for Materials, Graduate School of Engineering, Mie University, Tsu, Mie, 514-8507, Japan.
³ Mie Global Environment Center for Education & Research, Mie University, Tsu, Mie, 514-8507, Japan.

Abstract

The development of photocatalysts that efficiently degrade organic pollutants is an important environmental-remediation objective. To that end, we report a strategy for the ready fabrication of oxygen-doped graphitic carbon nitride (CN) with engendered nitrogen deficiencies. The addition of KOH and oxalic acid during the thermal condensation of urea led to a material that exhibits a significantly higher pseudo-first-order rate constant for the degradation of bisphenol A (BPA) (0.0225 min^-1) compared to that of CN (0.00222 min^-1). The enhanced photocatalytic activity for the degradation of BPA exhibited by the dual-defect-modified CN (Bt-OA-CN) is ascribable to a considerable red-shift in its light absorption compared to that of CN, as well as its modulated energy band structure and more-efficient charge separation. Furthermore, we confirmed that the in-situ-formed cyano groups in the Bt-OA-CN photocatalyst act as strong electron-withdrawing groups that efficiently separate and transfer photo-generated charge carriers to the surface of the photocatalyst. This study provides novel insight into the in-situ dual-defect strategy for g-C₃N₄, which is extendable to the modification of other photocatalysts; it also introduces Bt-OA-CN as a potential highly efficient visible-light-responsive photocatalyst for use in environmental-remediation applications.