Rational design of bimetal phosphide embedded in carbon nanofibers for boosting oxygen evolution

The development of non-precious metal electrocatalysts for oxygen evolution reaction (OER) is crucial for generating large-scale hydrogen through water electrolysis. In this work, bimetal phosphides embedded in electrospun carbon nanofibers (P-FeNi/CNFs) were fabricated through a reliable electrospinning-carbonization-phosphidation strategy. The incorporation of P-FeNi nanoparticles within CNFs prevented them from forming aggregation and further improved their electron transfer property. The bimetal phosphides helped to weaken the adsorption of O intermediate, promoting the OER activity, which was confirmed by the theoretical results. The as-prepared optimized P-Fe1Ni2/CNFs catalyst exhibited very high OER electrocatalytic performance, which required very low overpotentials of just 239 and 303 mV to reach 10 and 1000 mA cm-2, respectively. It is superior to the commercial RuO2 and many other related OER electrocatalysts reported so far. In addition, the constructed alkaline electrolyzer based on the P-Fe1Ni2/CNFs catalyst and Pt/C delivered a cell voltage of 1.52 V at 10 mA cm-2, surpassing the commercial RuO2||Pt/C (1.61 V) electrolyzer. It also offered excellent alkaline OER performance in simulated seawater electrolyte. This demonstrated its potential for practical applications across a broad range of environmental conditions. Our work provides new ideas for the ration design of highly efficient non-precious metal-based OER catalysts for water electrolysis.

Biomass-Derived Carbon-Based Multicomponent Integration Catalysts for Electrochemical Water Splitting

Electrocatalytic water splitting powered by sustainable electricity is a crucial approach for the development of new generation green hydrogen technology. Biomass materials are abundant and renewable, and the application of catalysis can increase the value of some biomass waste and turn waste into fortune. Converting economical and resource-rich biomass into carbon-based multicomponent integrated catalysts (MICs) has been considered as one of the most promising ways to obtain inexpensive, renewable and sustainable electrocatalysts in recent years. In this review, recent advances in biomass-derived carbon-based MICs towards electrocatalytic water splitting are summarized, and the existing issues and key aspects in the development of these electrocatalysts are also discussed and prospected. The application of biomass-derived carbon-based materials will bring some new opportunities in the fields of energy, environment, and catalysis, as well as promote the commercialization of new nanocatalysts in the near future.

Rational construction of yolk-shell CoP/N,P co-doped mesoporous carbon nanowires as anodes for ultralong cycle life sodium-ion batteries

Owing to the natural abundance and low-cost of sodium, sodium-ion batteries offer advantages for next-generation portable electronic devices and smart grids. However, the development of anode materials with long cycle life and high reversible capacity is still a great challenge. Herein, we report a yolk–shell structure composed of N,P co-doped carbon as the shell and CoP nanowires as the yolk (YS–CoP@NPC) for a hierarchically nanoarchitectured anode for improved sodium storage performance. Benefitting from the 1D hollow structure, the YS–CoP@NPC electrode exhibits an excellent cycling stability with a reversibly capacity of 211.5 mA h g⁻¹ at 2 A g⁻¹ after 1000 cycles for sodium storage. In-depth characterization by ex situ X-ray photoelectron spectroscopy and work function analysis revealed that the enhanced sodium storage property of YS–CoP@NPC might be attributed to the stable solid electrolyte interphase film, high electronic conductivity and better Na⁺ diffusion kinetics.

Owing to the natural abundance and low-cost of sodium, sodium-ion batteries offer advantages for next-generation portable electronic devices and smart grids.

Preparation of CeO2@C nanomaterials by adsorption of metal ions on microbial waste

The use of microbial adsorption for metal ions to prepare novel carbon-supported metal nanomaterials has attracted growing research attention. However, the relationship between the adsorbed metal content and catalytic performance of the resulting nanomaterials is unclear. In this work,Pichia pastoris residueswas utilized to adsorb Ce(Ⅲ) at different metal ion concentrations, and then CeO₂@C nanomaterials were prepared by pyrolysis. The effects of solution pH and adsorption behavior were investigated. The prepared nanostructures were characterized using electron microscopy and different spectroscopy methods, and their catalytic performances in the removal of salicylic acid from solution by catalytic ozonation were invested. The microbial residue had a metal uptake of 172.00 ± 2.82 mg· g^-1at pH 6. In addition, the efficiency of total organic carbon (TOC) removal increased from 21.54% to 34.10% with an increase in metal content in the catalysts from 0 mg· g^-1to 170.05 mg· g^-1. After pyrolysis, the absorbed Ce(Ⅲ) metal transformed to CeO₂metal nanoparticles embedded in a carbon matrix and had a core-shell CeO₂@C structure. Therefore, this work not only reveals a relationship between metal content and catalytic performance, but also provides an approach for studying performance of materials with different metal contents loaded on various carriers.

Highly clean and efficient iron phosphates modified by Ru nanocrystals for water oxidation

Optimizing the architecture of non-polluting, highly efficient, robust, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is extremely crucial for accelerating the application of water splitting. Herein, a highly green and active OER electrocatalyst composed of Ru nanocrystal modified iron-rich phosphates is successfully developed via a hydrothermal and post-annealing approach. The eco-friendly phosphorus source of lecithin is employed to fabricate transition metal phosphates for the first time, which avoids the use of toxic and dangerous phosphorus sources. Meanwhile, it is found that Ru nanocrystals could form heterostructures with iron phosphates and induce conversion to iron-rich phosphates, which would greatly enhance the conductivity of the substrate and elevate the catalytic activity. As a result, overpotentials of only 250 mV and 290 mV are required to deliver 10 and 100 mA cm^-2 using this typical electrocatalyst. Also, the j-t curve shows no distinct variations in current over 45 h at a constant overpotential of 334 mV, indicating the outstanding activity and durability of the catalyst. Furthermore, nickel/cobalt-rich phosphates and phosphides were also acquired using similar experimental procedures, manifesting the wide applicability of Ru actuation. Hence, this work offers a convenient and scalable method for designing highly efficient, green, clean, and cost-effective electrocatalysts for water splitting.