Graphitic carbon nitride (g-C₃N₄) has emerged as a promising metal-free polymeric semiconductor with immense transformative potential in solar-driven energy conversion and environmental remediation, underpinned by its thermodynamically favorable band structure for key redox reactions, exceptional chemical and thermal stability, low-cost scalable synthesis, and adjustable visible-light responsiveness. However, its practical industrial exploitation remains severely hampered by three intrinsic bottlenecks: ultrafast recombination of photogenerated electron-hole pairs that drastically reduces quantum efficiency, inadequate visible-light absorption region that limits full-spectrum solar utilization, and a scarcity of active surface sites that restricts overall reaction performance. To overcome these long-standing intrinsic bottlenecks, biomass-based functionalization has emerged as a rapidly growing research frontier, offering a sustainable, low-cost alternative to conventional high-input chemical modification strategies. As the most abundant renewable carbon feedstock on Earth, biomass providing a uniquely versatile and green platform for the rational engineering of g-C₃N₄. In this review, we systematically summarize state-of-the-art recent advances in biomass-engineered g-C₃N₄ photocatalysts, elaborate their core regulatory functions and underlying enhancement mechanisms, and provide critical theoretical references for future research in this rapidly evolving field.

Piezocatalysis provides a promising, sustainable route for onsite H₂O₂ production from ubiquitous mechanical energy. However, current piezocatalytic systems are predominantly based on inorganic materials, while organic piezocatalysts have received limited attention. Herein, we report a conjugated donor-acceptor (D-A) polymer prepared via a facile one-step polycondensation method, and systematically explore its piezocatalytic performance for H₂O₂ production. The as-prepared D-A polymer achieves a remarkable piezocatalytic H₂O₂ production rate of 4.3 mmol g^-1 within 30 min, outperforming the majority of previously reported organic and inorganic piezocatalysts. Experiments and DFT computations demonstrate that the delocalized conjugated backbone facilitates efficient charge migration within the D-A polymer. The spatially segregated frontier molecular orbitals effectively inhibit undesirable charge carrier recombination. Meanwhile, periodic mechanical strain dynamically modulates the reaction thermodynamics through optimizing the adsorption energy of reactants and desorption energy of H₂O₂. This work not only develops an efficient metal-free organic piezocatalyst for sustainable onsite H₂O₂ synthesis, but also offers critical theoretical guidance for the rational design of advanced organic piezocatalytic materials.

Using anion exchange membrane water electrolysis (AEMWE) technology to produce hydrogen is one of the effective pathways for future energy development. Designing efficient and stable anode oxygen evolution reaction (OER) catalysts is crucial for improving hydrogen production efficiency. In this study, Fe-doped Ni₂P material was designed using a MOF as a precursor, and then combined with CoP nanowire arrays to form Fe-Ni₂P@CoP heterojunction composite. Different from previous reports, this work features precise Fe doping (~3.6 at%), a unique 0D/1D morphology, and systematic AEMWE evaluation at 1.0 A cm^-2. It is found that doping and interface engineering induce charge transfer between Fe atoms and the heterojunction interfaces, optimizing the overall electronic structure and enhancing the adsorption of reaction intermediates at the active sites, thereby improving electrocatalytic performance. The Fe-Ni₂P@CoP catalyst demonstrates highly efficient OER activity and requires only 276 mV overpotential to achieve a current density of 100 mA cm^-2, maintaining stability for 100 hours. Subsequently, it is assembled with Pt/C into an AEM electrolyzer, achieving a cell voltage of only 1.77 V at a high current density of 1.0 A cm^-2 relevant to industrial applications, demonstrating promising potential for industrial hydrogen production under specific AEMWE operating conditions.

Fast-charging aqueous zinc-ion batteries (AZIBs) have advanced rapidly owing to their intrinsic safety, low cost and the longer Sand's time of divalent Zn²⁺, which can delay ion-depletion-limited failure compared with monovalent Li⁺. Nevertheless, the divalent nature also imposes sluggish desolvation and interfacial charge-transfer kinetics, making fast zinc deposition highly susceptible to polarization, dendrite growth, parasitic reactions, and rapid capacity decay. Existing reviews mainly classify materials and strategies, whereas the field lacks a scale-resolved framework explaining where fast-charging failure originates, how it propagates and when it becomes irreversible. Here we propose a polarization-driven “three contradictions” framework for AZIBs, in which microscopic ion-electron transport mismatch generates polarization, mesoscale kinetics-uniformity conflict amplifies nonuniform deposition, and macroscopic electrochemical stability window (ESW)-limited rate-capacity trade-off converts accumulated overpotential into capacity loss and full-cell failure. By mapping desolvation design, foil/powder electrode engineering and wide-window electrolyte strategies onto these three stages, we further propose practical evaluation protocols based on DOD_Zn, cumulative plating capacity (CPC), E/C ratio, N/P ratio and full-cell validation, providing a roadmap from high-rate laboratory demonstrations toward application of AZIBs under XFC conditions.

Ammonia (NH₃) is a key chemical feedstock, a carbon-free fuel, and a hydrogen carrier, yet its production still relies on the energy- and emission-intensive Haber-Bosch process. Electrocatalytic nitrate reduction (eNO₃^-RR) offers a sustainable alternative, converting NO₃^- and water to NH₃ under ambient conditions, but it demands catalysts that combine high activity, selectivity, and stability. Two-dimensional transition-metal carbides, nitrides, and carbonitrides (MXenes) are promising candidates because of their high electrical conductivity, large surface area, and tunable surface chemistry, although their use in eNO₃^-RR remains underexplored. This review covers the mechanisms of nitrate-to-ammonia conversion and the synthesis of MXenes, then analyzes how noble-metal decoration, alloying, hybridization with metal compounds, and single-atom engineering shape catalytic performance. It also examines how machine-learning-assisted computational modeling can predict and optimize MXene-based catalysts. Finally, key challenges and future directions are outlined to guide the rational design of MXene electrocatalysts for green ammonia synthesis.