Hydrogen energy has attracted considerable attention as a potential renewable energy source. The hydrogen evolution reaction (HER) of electrocatalytic hydrolysis is regarded as the cleanest, most reliable, and simplest method for generating high-purity hydrogen. This research made extensive use of the special structural properties of conjugated microporous polymers (CMPs), namely a high surface area and microporous structure, for the development of novel electrocatalysts in HER.
Ni-TBPP-CMP was synthesised with Ni metalloporphyrin monomers, and exhibits a high specific surface area of 441 m2 g-1 and a micro-mesoporous pore structure. The introduction of Ni-TBPP has been shown to effect a significant improvement in the HER catalytic activity of CMPs. The HER exhibited an overpotential value of 279 mV at a current density of 10 mA cm-2 in a 0.5 M H2SO4 electrolyte, which is superior to that of the majority of other metalloporphyrin-based catalysts. Moreover, the synthesis of Pyrene-Ni-TBPP-CMP materials was achieved by means of the introduction of a pyrene monomer onto Ni-TBPP-CMP catalysts. The introduction of the monomer pyrene has been demonstrated to exhibit a catalytic activity enhancement of CMPs in HER. The specific surface area of Ni-TBPP-CMP was increased (506 m2 g-1), an overpotential value of 201 mV was observed with a current density of 10 mA cm-2, and a low Tafel slope (103.2 mV dec-1) was noted. Moreover, the electrochemical surface area was considerable (0.233 mF cm-2), and the catalyst exhibited robust stability (7.5% overpotential loss rate) after 2000th CV cycle.
Environmentally friendly and economically viable CMP catalysts, which are metal-free nitrogen-atom-doped PP-CMP electrocatalysts, were successfully synthesised. The material displays a high specific surface area of up to 547 m2 g-1 and an extensive pore structure. PP-CMP exhibits remarkable HER catalytic performance, with an overpotential of 214 mV at 10 mA cm-2. Furthermore, it displays fast reaction kinetics (95.6 mV dec-1), a large electrochemical surface area (0.296 mF cm-2), and excellent stability after the 1000th CV cycle, with an overpotential loss of 12 mV. These positions PP-CMP for practical applications in green hydrogen production.
The results underscore the critical importance of optimizing CMP structure and composition to enhance electrocatalytic performance. The introduction of functional groups, including pyrene incorporation and nitrogen doping, has been demonstrated to significantly improve both catalytic activity and material stability. Compared to other materials in related research fields, the CMP-based electrocatalysts developed in this study exhibit exceptional HER performance. These findings provide valuable insights for designing next-generation electrocatalysts. Recent advancements in various CMP-based electrocatalysts, offering improved cost-effectiveness and practical applicability, have emerged as a pivotal research focus - representing a significant step forward in electrocatalytic hydrogen evolution.
