Photoelectrocatalytic hydrogen production is a sustainable energy technology that utilizes solar energy to decompose water into hydrogen and oxygen. It offers the advantages of environmental protection and sustainability. However, its low efficiency in photoelectric water splitting results in relatively small hydrogen production, which severely limits its popularization in practical applications. This paper reviewed the technology of photoelectric catalytic hydrogen production, including the principle of photoelectric catalysis, catalyst materials, reaction mechanism and kinetics, reaction conditions and optimization, as well as the challenges and prospects. The catalysts for efficient hydrogen production as well as the strategies for improving hydrogen production rate were discussed in detail, including the use of catalysts, co-catalysts, integrated optimization of reaction conditions and photoelectrodes. It also covered research on reaction kinetics, multi-physical field simulation and optimization. The paper provided a comprehensive theoretical basis and practical guidance for research in related fields.

The N-doping strategy is considered an effective method to regulate the electronic structure of carbon materials and improve their electrochemical performance. However, how to reasonably regulate the types of N-doping species remains a major challenge. Herein, we reported a self-supporting carbon nanofiber electrode codoped with N and Se (N/Se-CNF) for flexible zinc ion capacitor (ZIC). It was found that Se atoms can induce the reduction of Pyrrole-N, which is favorable for Zn ions transfer. Furthermore, ex-situ characterizations and theoretical density functional theory (DFT) calculations have shown that additional Se atoms can provide abundant reaction sites and reduce the adsorption energy of Zn ions. Accordingly, the N/Se-CNF electrode demonstrates impressive rate performance. The N/Se-CNF electrode shows impressive rate performance, retaining 60% capacitance at 20 A·g^–1, with an energy density of 95.3 Wh·kg^–1 and power density of 160.1 W·kg^–1, and a commendable stability cycle, the capacitance retention is 88.1% after 18,000 cycles at a discharge rate of 5 A·g^–1. Moreover, a flexible ZIC with N/Se-CNF electrode exhibits a high energy density of 68.8 Wh·kg^–1 at 160 W·kg^–1. This strategy innovatively regulates N-doping species and offers potential flexible electrodes for advanced energy storage devices.

In the contemporary context, tetracycline is widely utilized as a prevalent antibiotic in various facets of life. However, the excessive use of antibiotics has caused visible environmental consequences. Henceforth, the scientific community has increasingly focused on developing catalysts that exhibit exceptional efficacy in the proficient degradation of tetracycline. In this study, a novel nanomaterial was developed to encapsulate CdTe quantum dots (QDs) with a SiO₂ shell. The distinct synthesis approach generated a composite material that showed heterogeneity and considerably increased the contact area with contaminants. Consequently, the transfer of photoelectron to the SiO₂ spheres was significantly improved, leading to a more efficient separation during the catalytic process. The study investigated how different factors, such as the loading of the catalyst, the initial concentration of tetracycline, pH levels, and the wight ratio of CdTe QDs (SiO₂ + CdTe QDs) affected the effectiveness of photocatalytic tetracycline degradation. The findings indicated that the optimal degradation efficiency was observed at a catalyst concentration of 0.25 g/L and a solution pH of 9, leading to an impressive degradation rate of 96% within a mere 2 h timeframe.

The development of efficient non-precious metal catalysts is important for the large-scale application of alkaline hydrogen evolution reaction (HER). Here, we synthesized a composite catalyst of Cu and Mo₂C (Cu/Mo₂C) using Anderson-type polyoxometalates (POMs) synthesized by the facile soaking method as precursors. The electronic interaction between Cu and Mo₂C drives the positive charge of Cu, alleviating the strong adsorption of hydrogen at the Mo site by modulating the d-band center of Mo₂C. By studying the interfacial water structure using in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), we determined that the positively charged Cu crystals have the function of activating water molecules and optimizing the interfacial water structure. The interfacial water of Cu/Mo₂C contains a large amount of free water, which could facilitate the transport of reaction intermediates. Due to activated water molecules and optimized interfacial water structure and hydrogen adsorption energy, the overpotential of Cu/Mo₂C is 24 mV at a current density of 10 mA·cm⁻² and 178 mV at a current density of 1000 mA·cm⁻². This work improves catalyst performance in terms of interfacial water structure optimization and deepens the understanding of water-mediated catalysis.

Herein, a unique mesoporous heterostructure (average pore size: 15 nm) cobalt disulfide/carbon nanofibers (CoS₂/PCNFs) composite with excellent hydrophilicity (contact angle: 23.5°) is prepared using polyethylene glycol (PEG) as a pore-forming agent. The CoS₂/PCNF electrode exhibits excellent cycle stability (95.2% of initial specific capacitance at 10 A∙g⁻¹ after 8000 cycles), good rate performance (46.5% at 10 A∙g⁻¹), and high specific capacity (86.1 mAh∙g⁻¹ at 1 A∙g⁻¹, about 688.8 F∙g⁻¹ at 1 A∙g⁻¹). Density functional theory (DFT) simulation elucidates that CoS₂ tends to transfer substantial charges to CNF. As the center of positive charge, CoS₂ is more likely to capture negative ions in the electrolyte, thus accelerating the ion diffusion process. The excellent properties of the electrode material can not only accelerate the electrochemical reaction kinetics, but also provide abundant redox-active sites and a high Faradaic capacity for the entire electrode due to the synergistic contributions of CoS₂ nanoparticles, mesoporous heterostructure of PCNF, and admirable hydrophilicity of the composite material. A CoS₂/PCNF-0.25//AC (AC: activated carbon) asymmetric supercapacitor is assembled using CoS₂/PCNF-0.25 as the positive electrode and AC as the negative electrode, which possesses a high energy density (35.5 Wh∙kg⁻¹ at a power density of 824 W∙kg⁻¹) and superior cycling stability (maintaining over 98% of initial capacitance after 2000 cycles). In addition, the unique CoS₂/PCNF electrode is expected to be widely used in other electrochemical energy storage devices, such as lithium-ion batteries, sodium-ion batteries, lithium-sulfur batteries, etc.