Single-atom (SA) decoration of 1D semimetallic titania nanostructures (STN): a conductive electrode for electrocatalytic hydrogen evolution (HER)

氢气是未来最有前途的可再生清洁能源。目前，工业生产氢气的基础是重整天然气，天然气在产生二氧化碳的同时使用大量不可再生能源。一种可持续和环境友好的制氢方法是电化学水分解。因此，提高电化学除水的效率并改善其经济性是世界各国研究的主要目标。催化剂的存在使析氢反应(HER)所需的过电位降至最低，这是提高水分解效率的关键。对她来说，铂是最知名的催化剂，主要是因为它需要非常小的过电位。然而，铂的高成本和稀缺性限制了其广泛的技术应用。通过为HER设计新的催化剂材料，研究人员旨在扩大他们对决定HER稳定性和活性的性质和表面结构的理解。本研究方案旨在利用单原子(SA)修饰的半金属二氧化钛(STN)作为HER的廉价、高效、高活性和长期稳定性的电极，建立一种新颖的、高精度的电催化氢气生成平台。该方法的主要创新点是将缺陷工程二氧化钛基半金属纳米结构与先进的单原子装饰策略相结合，制造出一个平台，用作绿色氢气生产行业的HER电极。预计，一维背接触(1D)结构中的定向电荷转移、单原子修饰和SA-STN组装中表面暴露的Ti3+中心的三个黄金特征的协同效应将导致HER活性的提高。作为概念验证，在该项目的最后一个工作包中，我们的目标是将优化后的HER电极植入商用聚合物电解质膜(PEM)电解槽，该电解槽将提供有关电极在标准和现场测量条件下的长期活性和稳定性的基准信息。

Hydrogen (H2) is the most promising future form of renewable clean energy source. Currently, industrial H2 production is based on reforming natural gas, which uses a high amount of non-renewable energy while producing carbon dioxide. A sustainable and environmentally friendly H2 production approach is electrochemical water splitting. Therefore, enhancing the efficiency and improving the economic aspects of electrochemical water splitting is a primary goal of research worldwide. The presence of a catalyst to minimize the overpotential required for the H2 evolution reaction (HER) is essential to enhance the efficiency of water splitting. Platinum is the most well-known catalyst for HER, mainly due to the fact that it requires very small overpotentials. However, the high cost and scarcity of Pt restrict its prevalent technological use. By designing new catalyst materials for the HER, researchers aim to expand their understanding of the properties and surface structures that govern HER stability and activity. The present research proposal aims at creating a novel and highly defined platform for electrocatalytic hydrogen generation using Single-Atom (SA) decorated Semimetallic Titania-based Nanocavities (STN) as a non-expensive and highly efficient electrode for HER with boosted activity and long-term stability. The key novelty of the proposed approach is the combination of defect-engineered titania-based semimetallic nanostructures with the advanced single-atom decoration strategy to fabricate a platform to be employed as an HER electrode in the green H2 production industry. It is expected that the synergistic effect of three golden features, i.e., i) directional charge transfer in a one-dimensional back contacted (1D) structure, ii) single atom decoration, and iii) surface-exposed Ti3+ centers in an SA-STN assembly, will lead to a boosted HER activity. As a proof of concept, in the last work package of the project, we aim to implant the optimized HER electrode in a commercial polymer electrolyte membrane (PEM) electrolyzer, which will provide benchmark information regarding the long-term activity and stability of the electrode in a standard and onsite measurement conditions.