In-situ Preparation Of Chlorine-induced TiO₂ Thin Film Electrode And Its Photoelectrocatalytic Performance

Nowadays,issues such as energy shortages,environmental pollution,and the greenhouse effect are becoming increasingly prominent.Photoelectrocatalytic technology?PEC?is considered as a technology with great application potential in the environment and energy fields.Ti O₂ is an ideal photoelectrode material because of its low cost,high activity,and non-toxicity.However,the application of PEC technology using Ti O₂ semiconductor as the photoelectrode is limited to some extent by the problems of low quantum efficiency,preparation cost and stability of semiconductor thin film electrodes.In this parper,in-situ grown Ti O₂ thin film electrode was prepared by hydrothermal method,and its application in the photoelectric reaction system of photoelectrocatalytic degradation of organic pollutants and simultaneous photoelectro-driven cathode to reduce CO₂ was studied.It provided an example for using PEC technology to simultaneously solve environmental and energy problems.A series of thin-film electrodes with two-dimensional leaf-like nanosheet morphology were prepared by hydrothermal treatment of titanium sheets in a solution containing sodium chloride?Na Cl?and hydrogen peroxide?H₂O₂?.The 0Cl-Ti O₂/Ti electrode and 0.1Cl-Ti O₂/Ti electrode with the best photoelectric response were calcined at three different temperatures to obtain six different electrodes.Physical and chemical characterization techniques such as X-ray diffraction?XRD?,field-emission scanning electron microscope?FE-SEM?,transmission electron microscope?TEM?,X-ray photoelectron spectroscopy?XPS?,and contact angle measurement were used to test and analyze the morphology and composition of the catalysts.Using UV-vis diffuse reflection?UV-vis?,photoluminescence spectrum?PL?,linear cyclic voltammetry?LSV?,time-current curve?i-t?,alternating current impedance?EIS?,and Mott-Schottky curve?MS?characterization techniques to test the photoelectrocatalytic performance of the catalysts.The results showed that the Cl element added in hydrothermal functions as a morphology control agent and a rutile phase inducer.The 450?0.1Cl-Ti O₂/Ti thin film electrode has smaller internal resistance and better photocurrent response.The in-situ generated chlorine-induced Ti O₂ thin-film electrode was used as the photoanode,and the hexagonal topless double-pyramid nanostructured H-Ag electrode prepared by the electrochemical pulse method was used as the cathode,which were separately placed in the 0.1 mol·L^-1Na₂SO₄ anolyte containing carbamazepine and the0.1 mol·L^-1KHCO₃ catholyte,the photoelectroncatalytic degradation of carbamazepine and simultaneous reduction of CO₂ were performed under the irradiation of light with a light intensity of 500 m W·cm^-2.450?0.1Cl-Ti O₂/Ti thin-film electrode exhibits excellent photoelectrocatalytic activity.At an applied voltage of 1.5 V,the degradation rate of carbamazepine is 73.08±1.67%,the removal rate of TOC is 25.67±1.26%,and the Faraday efficiencies of cathode reduction product carbon monoxide?CO?and formic acid?HCOOH?are 36.91±1.21%and 3.86±0.08%,respectively.Seven cycles of experiments have proved that it has good stability.In addition,the effects of different potentials and different pollutants on the photoelectrocatalytic activity were also explored.By using LC-MS to detect intermediates and capture agent experiments,a possible degradation pathway of carbamazepine in PEC reaction was proposed.According to the related literature and experimental research,a possible path for reducing CO₂ to CO and HCOOH by photoanode photoelectrochemical-driven the H-Ag electrode is also proposed.