Zinc oxide-graphitic carbon nitride nanohybrid as an efficient electrochemical sensor and photocatalyst

Abstract

In this study, zinc oxide-graphitic carbon nitride (ZnO-CN) nanohybrid has been synthesized via a facile in-situ one pot solid-state thermal decomposition method, here [Zn(hmp-H)2(H2O)(μ-Cl)Zn(μ-Cl)(Cl)3] was used as single-source molecular precursor (SSMP) for ZnO and urea was taken as a source for graphitic carbon nitride (CN). Synthesized ZnO-CN nanohybrid was used as a modifier towards the fabrication of a binder free glassy carbon electrode surface (ZnO-CN/GCE) for detection of –NO2 containing aromatic compounds. The developed sensor shows the remarkable sensitive lower detection limit responses of 100 nM, 110 nM, 202 nM towards the 4-nitrotoluene (4-NT); 2,4-dinitrotuluene (2,4-DNT); 2,4,6-trinitrophenol (2,4,6-TNP), respectively. Further, a superior and rapid photo-catalytic degradation of Chicago Sky Blue (CSB), Congo Red (CR) and Methylene Blue (MB) was also achieved by employing ZnO-CN as a photo-catalyst with the percentage degradation of ∼85-99.6%. The alluring performance of the ZnO-CN nanohybrid towards the sensing of -NO2 containing aromatics and degradation of organic pollutants was ascribed to high surface area of as synthesized nanohybrid and heterojunction formed between the interfaces of ZnO and graphitic carbon nitride. These properties may facilitate the electron transfer process due to the higher electron conductivity and the separation of photo-induced electron−hole pairs. © 2018 Elsevier B.V.