Photo-renewable electrode based on porous carbon-loaded La-TiO2 for detection of catechol and hydroquinone

The fouling and passivation of the electrodes tend to reduce the sensitivity and lifetime of the electrodes. In this work, the mesoporous carbon-doped La-TiO 2 modified electrode not only has a good detection signal for catechol and hydroquinone, but also can achieve the purpose of electrode regeneration under illumination. A series of porous carbon materials LTOF-T (La-Ti Organic Frameworks-Temperature, LTOF-T) were prepared by hydrothermal method and pyrolysis method using La(NO 3 ) 3 ⋅6H 2 O, p -tricarboxylic acid, citric acid monohydrate, and tetra- n -butyl titanate as raw materials. The materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N 2 adsorption–desorption, and Raman spectroscopy. The electrochemical behaviors of catechol (CA) and hydroquinone (HQ) on different electrodes were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal conditions, HQ and CA concentrations were linear in the range of 0.4–20 μmol/L, and the detection limits were 0.039 μmol/L (HQ) and 0.034 μmol/L (CA) at the signal noise ratio of 3. The electrode can be regenerated under visible light irradiation within 60 min.