Aijian Wang

Covalent organic polymers (COPs) have attracted considerable attention as electrocatalysts because of their tunable structures, high porosity, and abundant functional sites, yet their practical application is often limited by poor electrical conductivity. Herein, conductive metalloporphyrin-based COP hybrids were synthesized through a quaternization-induced polymerization strategy in the presence of multi-walled carbon nanotubes (MWCNTs). The resultant FeTPyPCOP@MWCNTs and NiTPyPCOP@MWCNTs integrate metalloporphyrin coordination sites, a porous polymer framework, and a conductive carbon network within a single architecture. A direct comparison between the two materials reveals that FeTPyPCOP@MWCNTs exhibit superior electrocatalytic activity toward water splitting, highlighting the important influence of the coordinated metal center. FeTPyPCOP@MWCNTs requires overpotentials of only 117 mV for the hydrogen evolution reaction (HER) and 241 mV for the oxygen evolution reaction (OER) at 10 mA cm–2. In a two-electrode electrolyzer, it delivers 10 mA cm–2 at a cell voltage of 1.56 V, together with excellent durability and near-quantitative Faradaic efficiency. This work demonstrates that combining metalloporphyrin coordination environments with conductive polymer/carbon architectures is an effective strategy for developing efficient bifunctional electrocatalysts for overall water splitting.

The hydrogen evolution reaction (HER) in alkaline media is central to sustainable hydrogen production but is limited by sluggish kinetics and catalyst instability. To connect fundamental chemistry, electrochemistry, and materials science with hands-on learning, we designed a laboratory experiment for undergraduate students to synthesize and evaluate a Mo3N2/Ni3Mo3N/Co3Mo3N triple-phase nitride electrocatalyst, composed of three integrated nitride phases. The ternary structure provides abundant active sites and efficient charge-transfer interfaces, which achieve a low overpotential of 33 mV at 10 mA cm–2, surpassing binary analogues and approaching the HER performance of the benchmark platinum-on-carbon (Pt/C) electrocatalyst. Students prepare working electrodes, characterize catalyst structure using X-ray diffraction and electron microscopy, and perform electrochemical HER measurements. Analysis of polarization curves, Tafel plots, electrochemical impedance spectroscopy data, and electrochemically active surface area, combined with guided comparisons between ternary and binary systems, enables students to relate structural features to the HER activity. This integrated approach demonstrates how multiphase design enhances HER activity, offering students insights into rational electrocatalyst design and sustainable energy research.

We synthesized hybrid electrocatalysts by covalently linking cobalt-porphyrin and phenanthroline units via alkyl dibromide spacers. CoTAPPPhen-C3 displayed the best HER activity with an overpotential of 108 mV at 10 mA cm ⁻² .

Novel hybrid electrocatalyst CoTAPPHIPA–CoTPPOH shows exceptional HER performance with low overpotentials due to enhanced charge transfer, conductivity, and active site density.

We developed a novel porous organic polymer electrocatalyst, Tp-FeTAPP, by covalently functionalizing iron–porphyrin with trimesaldehyde phloroglucinol. This catalyst exhibits exceptional HER activity with remarkably low overpotential.

To develop eco-friendly low-temperature NH₃-SCR catalysts for the non-electric industry, a series of CeMn-modified Ba₂Ti₅O₁₂ catalysts were synthesized using the sol-gel method to achieve denitrification. Activity tests revealed that Ce-Mn-modified Ba₂Ti₅O₁₂ catalysts exhibit excellent low-temperature denitrification performance with a broad operational temperature window. Characterization through XRD, XPS, BET, NH₃-TPD, and EPR indicated that Ce-Mn modification enhances surface oxygen chemisorption and increases acidity, significantly improving NO_x reduction. Notably, the optimal catalyst achieved NO_x conversion rates exceeding 90% within the temperature range of 90 to 240 °C under a gas hourly space velocity (GHSV) of 28,000 h⁻¹. In particular, the coexistence of Ce and Mn species promotes the oxidation of NO to NO₂, facilitating the “fast SCR” reaction. The abundance of valence states further enhances the catalyst’s ultra-low-temperature NH₃-SCR denitration performance.

Photocatalytic denitrification is a promising approach for environmental remediation and solar energy conversion. In this study, a series of Bi₂Ti₂O₇/BaTiO₃ heterojunctions were synthesized via hydrothermal method, demonstrating superior photocatalytic NO removal efficiency (94%) compared to individual components. Comprehensive characterizations confirmed the formation of a tightly coupled heterojunction with enhanced visible‐light absorption and charge separation. Optical and electrochemical analyses revealed that the composite facilitates efficient electron‐hole separation (supported by reduced PL intensity and lower charge‐transfer resistance in EIS) while retaining strong redox potentials, consistent with an S‐scheme charge‐transfer mechanism. Additionally, the increased surface area (BET) and porosity further promote reactant adsorption. Trapping experiments and electron paramagnetic resonance (EPR) confirmed that e⁻, h⁺, and ·O₂⁻ are key reactive species. The synergistic effects of improved charge dynamics, optimized light utilization, and interfacial electron transfer collectively contribute to the enhanced photocatalytic performance.

Correction for ‘Innovative bipyridine-bridged metal porphyrin polymer for Robust and superior electrocatalytic hydrogen evolution’ by Xiaoyu Zhai et al., Chem. Commun., 2025, https://doi.org/10.1039/D5CC00665A.