海洋环境腐蚀与生物污损重点实验室知识库

外加电流的阴极保护法作为一种有效的腐蚀防护技术，广泛应用于管道等钢铁结构的腐蚀防护工程。但是，在远海岛礁等无市电供应电流的区域，由于受到跨海供电困难等因素，阴极保护难以发挥其作用。因此，开发太阳能等以自然能源为驱动的阴极保护系统成为解决这一问题十分有效的办法。然而，由于太阳能发电受到白昼黑夜交替等因素影响，往往存在间歇性工作的缺点，难以维持阴极保护系统中电流供应的持续性和稳定性，这也是目前光电化学阴极保护实现实际应用的一大关键阻碍。为解决这一难题，在光电化学阴极保护系统中引入可以储能的电化学器件，将太阳能电池工作状态下富余的电能进行储存，在太阳能电池无法正常工作的情况下，由储能设备给阴极保护系统提供持续的保护电流，从而保证被保护的金属得到持续的防护。

因此，本研究工作首次在实验室搭建了基于太阳能—储能电池的阴极保护应用示范及测试系统。针对高性能储能电池电极材料的研发制备进行了较为系统的探索，以新型二维纳米材料Ti₂C₃为基础活性物质，通过氧化钌、二氧化锰、氧化锡等储能活性材料的复合以及改性、活性物质三维结构的构建，提高材料在储能电极应用时的容量以及循环寿命等性能，进一步组装超级电容器、锂离子电池等高性能的储能元件，并将其耦合进光电化学阴极保护系统之中，实现稳定可持续的电化学阴极保护。

研究内容包含以下3点：

1.制备了磷酸离子修饰的RuO₂/ Ti₃C₂超级电容器电极材料，Ti₃C₂片层可以有效防止纳米RuO₂颗粒的团聚，同时使得更多的RuO₂活性点暴露在电解液环境中，提高了RuO₂利用率；同时，Ti₃C₂独特的手风琴结构有利于电荷以及物质的转移；值得一提的是，磷酸根离子的修饰可以减小氧化钌在氧化还原反应过程中得电子壁垒，提高了RuO₂反应活性。因此，基于磷酸离子修饰的RuO₂/ Ti₃C₂超级电容器表现出良好的电化学性能，将该电容器连接到光电化学阴极保护系统中，能在暗态时替代太阳能电池为被保护金属提供持续而稳定的保护电流。

2.将表面改性后的碳纳米管（CNT）与Ti₃C₂通过静电荷吸引作用相互桥接，然后利用液相合成的方法在其表面沉积纳米氧化锰赝电容材料得到Ti₃C₂/ CNT/ MnO₂复合材料。纳米MnO₂颗粒的引入可以防止层间堆叠从而为电解液中提供扩散通道。同时，金属氧化物纳米颗粒可以贡献较大的赝电容。碳纳米管的引入起到桥接Ti₃C₂不同片层之间的作用，赋予了复合材料较高的导电性。将Ti₃C₂/ CNT/ MnO₂应用于超级电容器电极中测试了其电化学性能，具有126.8 F g^-1高比容量，以及突出的倍率性能和循环稳定性。将其用在阴极保护系统中时，也可以作为备用供电电源，给被保护金属提供电子。

3.通过静电荷吸引作用将Ti₃C₂与碳纳米管进行复合，制备具有良好导电性的Ti₃C₂/ CNT基体骨架，然后利用水热合成的方法将SnO₂负载在Ti₃C₂之上制备得到Ti₃C₂/ CNT/ SnO₂复合材料。将复合材料组装在锂离子电池电极中，具有506.9 mAh g^-1的容量，在循环100圈之后，容量仍能维持在89.32%。将其耦合进电化学阴极保护系统中，在暗态时为阴极保护提供恒定持久的电流供应，为阴极保护系统的稳定运行提供可靠地保障。

As an effective electrochemical anti-corrosion technology, Impressed Current Cathodic Protection (ICCP) is widely used in anticorrosion engineering. However, cathodic protection is difficult to play its role in areas where there is no mains supply current, such as islands and reefs in the open sea. Therefore, the development of cathodic protection system driven by solar energy has become an effective way to solve this problem. However, due to the alternation of day and night, solar power generation often suffer from the disadvantage of intermittent, which is difficult to maintain the continuity and stability of current supply. This is also a key obstacle for the practical application of photo-electrochemical cathodic protection technology. In order to solve this problem, electrochemical energy storing devices are introduced into the photo-electrochemical cathodic protection system to store the surplus electric charge in the working state of the solar cell. Under the condition that the solar cell cannot work normally, the energy storage device provides continuous current to the cathodic protection system.

Therefore, for the first time, a cathodic protection system based on solar cell and energy storage battery was established in this work. Our research mainly focuses on the development of high-performance electrode materials. According to the material modification and three-dimensional structure design, a series of materials based on Ti₂C₃ were prepared. Ruthenium oxide, manganese dioxide, tin oxide were selected as active substances. Through the reasonable composites design, a series of high-performance energy storage device were assembled. After coupling the energy storage device into the photo-electrochemical cathodic protection system, stable sustainable electrochemical cathodic protection system were established.

Specific research contents include the following contents:

1. A phosphate ion-modified RuO₂/Ti₃C₂ composite was prepared. In this composite material, Ti₃C₂ layers were introduced to prevent the RuO₂ particles from agglomeration. Thus, more active sites were exposed to the electrolyte, which improved the utilization rate of RuO₂. At the same time, the unique accordion structure of Ti₃C₂ would facilitate the charge transfer and material diffusion, which improved the rate performance of the supercapacitor. When coupled into the photoelectric chemical cathodic protection system, the phosphate ion-modified RuO₂/Ti₃C₂ based supercapacitor can replace the solar cell to provide continuous and stable protection current in the dark state.

2. Ti₃C₂/ CNT/ MnO₂ composites were prepared by depositing nanometer manganese oxide on the surface of Ti₃C₂/ CNT according to the electrostatic attraction. The introduction of nanometer MnO₂ particles could prevent the Ti₃C₂ layers form stacking and thus provide a diffusion channel for the electrolyte. At the same time, metal oxide nanoparticles can provide additional capacity and improve the electrochemical performance of supercapacitors. The introduction of carbon nanotubes act as a bridge between the different layers of Ti₃C₂, giving the composite higher conductivity. The electrochemical properties of Ti₃C₂/ CNT/ MnO₂ composite based supercapacitor delivered a high capacity of 126.8 F g^-1, rate performance and long cycling stability. When the supercapacitor was used as power supply in the cathodic protection system, it can provide electrons for the protected metal.

3. Ti₃C₂/ CNT skeleton were prepared according to the electrostatic attraction. Then, SnO₂ was deposed on Ti₃C₂ layers by a facile hydrothermal process to get Ti₃C₂/ CNT/ SnO₂ composite. Electrochemical test results showed that Ti₃C₂/ CNT/ SnO₂ delivered a high capacity of 506.9 mAh g^-1.What’s more, the capacity can still maintain 89.32% even after 100 cycles. When coupled the Ti₃C₂/ CNT/ SnO₂ based lithium ion battery into the electrochemical cathodic protection system, the battery would provide a constant and lasting current supply for the cathodic protection in the dark state, which ensures the stable operation of the cathodic protection system.