Modular design of solar-powered photocathodic metal protection device

Metal corrosion leads to severe economic losses and safety hazards to human society. As an energy-efficient and sustainable anticorrosion technique, photocathodic protection (PCP) systems have received growing attention in the past two decades. However, the existing PCP devices barely meet the requirements of adequate metal protection in real-world scenarios. This perspective aims to provide some constructive insights into the rational design of PCP devices and propose “functional module integration” as a new concept for future PCP systems. Similarly to multi-layered solar cells, PCP systems may incorporate multiple modules based on the corresponding functions. These include photoabsorber module (PAM), electron transfer module (ETM), hole transfer module (HTM), hole consumption module (HCM), and electron storage module (ESM). With such a modular design, improved capture of sunlight and fast charge separation, directional transportation, and effective utilization of the photogenerated carriers might be attained. Consequently, the solar-to-electric energy conversion efficiency and operation consistency of PCP devices can be significantly boosted, paving the way for practical application of solar-powered metal protection technology. Graphical Abstract: [Figure not available: see fulltext.]