Metal-organic frameworks derived ZnO-Co3O4 pn heterojunction photocatalyst for the photoelectrochemical detection of sulfadiazine

Semiconductors with abundant surface areas have received substantial attention in the field of sensors, especially for the specific and sensitive detection of molecules. Eco-friendly synthesis of metal oxides pn junction composite with high specific surface area and its photoelectrochemical monitoring on antibiotics have been reported. The ZnO-Co3O4 pn heterojunction composite has successfully been prepared from a metal-organic framework (MOF) as a template, using benzene tricarboxylic acid (BTC) with a one-step calcination process. In research, obtained nanorods like ZnO-Co3O4 pn heterojunction exhibited high conductivity with excellent stability for the facilitated photocatalytic performance towards the photoelectrochemical detection of sulfadiazine (SDZ). Photo-stability and the optical characteristics of the ZnO-Co3O4 heterojunction composite have been analyzed in photocurrent and UV-visible studies. A mechanism of SDZ signaling has been proposed with appropriate band levels derived by Mott-Schottky analysis. The proposed sensor detects SDZ in the range of 0.005-18.5 mu M with 1.2 nM as detection limit and exhibits better signaling stability. The applicability of the sensor device has been tested in pork meat, human urine, and river water samples containing SDZ.

Automated summary

This study presents an eco-friendly synthesis method for a metal oxide pn junction composite with high specific surface area, which has been successfully applied in photoelectrochemical monitoring. The ZnO-Co3O4 pn heterojunction composite exhibited high stability and conductivity for the detection of sulfadiazine.