A strategy for effective electrochemical detection of hydroquinone and catechol: Decoration of alkalization-intercalated Ti3C2 with MOF-derived N-doped porous carbon

The functional groups on the surface of Ti3C2 can be tailored by alkalization treatment to design novel electrode materials. However, the restacking of Ti3C2 greatly hinders its practical application. To address this limitation, a facile self-assembling method was developed to engineer a novel type of heterostructure (Ti3C2/MOF). The structure alk-Ti3C2/N-PC was prepared by combining MOF-5-NH2-derived nitrogen-doped porous carbon (N-PC) with alk-Ti3C2 prepared by the acid etching and alkaline intercalation treatment of Ti3C2. This strategy could effectively prevent Ti3C2 sheets from restacking and enable the sensing of benzenediol through hydrogen-bond interaction, brought about by the abundant -OH functional groups on the alk-Ti3C2 and numerous C-N bonds on N-PC. Because of the advantages of the excellent electrical conductivity of alk-Ti3C2 and the large surface area of N-PC, hydroquinone (HQ) and catechol (CT) could be detected on the basis of their benzenediol/benzoquinone redox reactions. Under optimized conditions, a wide linear range of 0.5-150 mu M with low detection limits of 4.8 nM (S/N = 3) and 3.1 nM (S/N = 3) for HQ and CT, respectively, were obtained. The alk-Ti3C2/N-PC electrochemical sensor was applied to detect HQ and CT in industrial wastewater, and acceptable recoveries were achieved. Hence, the decoration of alk-Ti3C2 with N-PC is an innovative method to engineer various alk-Ti3C2-based composites for the detection of phenolic isomers and environmental analyses.