类石墨烯二硫化物Mo(1-x)WxS2(0≤x≤1)对海工混凝土的光电化学阴极保护及其抗腐蚀机理研究

As a new type of green corrosion preventive technology, the photoelectrochemical cathodic protection could protect the metal from corrosion based on the photovoltaic effect of semiconductor materials. However, the semiconductor photoanode suffers from ineffective utilization of visible light due to its large band gap and low photoelectrochemical anticorrosion property because its conduction band position is not negative enough, which limits the wide application of photoelectrochemical cathodic protection in the field of anti-corrosion protection for marine reinforced concrete structure..This project proposes the disulfide Mo(1-x)WxS2(0≤x≤1) as the photoanodes of the photoelectrochemical cathodic protection for marine reinforced concrete structure, which are visible-light-respondent materials with more negative conduction band and graphene-like two-dimensional structure. In this work，the Mo(1-x)WxS2(0≤x≤1) anodes are designed based on the concept of regulating their electronic structure and band structure by doping modification and morphology control. This project will explore the effect of the chemical composition, crystal structure and morphology of Mo(1-x)WxS2(0≤x≤1) anodes on their cathodic polarization properties, investigate the mechanism of chlorine ion migration and distribution in the concrete, reveal the action of chlorine ion on the steel surface passivation film, demonstrate the structure-activity relationship between the structure of Mo(1-x)WxS2(0≤x≤1) anodes and their photoelectrochemical cathodic protection performance, and therefore confirm the photoelectrochemical anti-corrosion mechanism of Mo(1-x)WxS2(0≤x≤1) on marine concrete reinforced structure. The project is expected to provide the experimental model and theoretical basis for the potential applications of photoelectrochemical cathodic protection on reinforced concrete, and improve the durability of marine reinforced concrete structure.

光电化学阴极保护是利用半导体材料的光伏效应来实现金属的腐蚀防护，是一种绿色环保的新型腐蚀防护方法。然而，它采用的半导体光阳极材料的禁带宽度较宽且导带电位不够负，导致其太阳光利用效率比较低，光生电子不能有效传输到被保护钢筋上，限制了其在海工混凝土结构腐蚀与防护中的应用。.本项目拟设计以Mo(1-x)WxS2(0≤x≤1)作为海工混凝土光电化学阴极保护的光阳极，因其兼具导带电位较负、可见光响应和类石墨烯层状结构。通过掺杂改性和形貌控制，调控Mo(1-x)WxS2(0≤x≤1)的电子结构和能带结构，研究结构变化对其光照/暗态下的阴极极化行为影响，探究氯离子在混凝土内部的迁移和分布规律，阐明氯离子对钝化膜作用规律，阐述Mo(1-x)WxS2(0≤x≤1)结构与其光电化学阴极保护性能之间的构效关系，揭示其光电抗腐蚀机理。本项目的开展为实现海工混凝土结构的光电化学阴极保护提供实验模型和理论依据。

本项目以硫化物为主要研究对象，因硫化铋兼具导带电位较负和禁带宽度较窄的特性，构筑了基于硫化铋-ZnO的光电化学阴极保护光阳极体系。通过改变电沉积溶液的组成，分别制备了具有纳米线结构和纳米片结构的ZnO，然后通过连续离子层吸附反应法在ZnO薄膜上沉积了硫化铋纳米颗粒，得到了不同组分比例、不同纳米结构硫化铋-ZnO复合物的光阳极。分别测试了所制备薄膜的结构、形貌和光吸收性能，研究了异质结存在对所制备薄膜的结构、形貌和光吸收性能的影响，并考察了不同吸附周期下沉积的异质结复合薄膜光阳极与其光电化学性能之间的构性关系。探究了在三种不同空穴捕获剂中硫化铋-ZnO系列复合薄膜光阳极对金属(304SS和Q235CS) 的保护效果；通过光致电流-电压曲线和电化学阻抗谱，进一步揭示了异质结构筑和结构调控对其光照/暗态下的阴极极化行为影响，阐述光阳极结构与其光电化学阴极保护性能之间的构效关系，揭示了其光电防腐蚀机理。.研究发现，异质结的存在成功拓宽纳米ZnO在可见光光区的光吸收范围。在可见光照射下，硫化铋-ZnO纳米线/片复合材料对金属304SS和Q235CS都起到了光电化学阴极保护作用且保护性能均优于纯纳米ZnO。硫化铋-ZnO纳米线薄膜光阳极对304SS和Q235CS的光生电流密度分别提高了3倍和6倍，光致开路电位分别提高了6倍和9倍；而硫化铋-ZnO纳米片薄膜光阳极对304SS和Q235CS的光生电流密度分别提高为4.3倍和8.8倍，光致开路电位分别提高为5.6倍和16倍。本项目所研究的三种无机空穴捕获剂的捕获空穴能力由高至低依次为：0.1M Na2S+0.2M NaOH、0.1M Na2SO4和3.5% NaCl，在三种电解质溶液中硫化铋-ZnO纳米线/片复合膜光阳极均能对304SS电极实施光电阴极保护，而对Q235 CS，仅能在0.1M Na2S + 0.2M NaOH溶液中起到光致阴极保护效果。.综上，本文开发出了性能优异的硫化铋-ZnO光电阴极保护材料，并分析了其性能提升机制，为进一步发展光电阴极保护光阳极材料提供了依据。

内容获取失败，请点击重试