Synergistic effects of hierarchical porous structures and ultra-high pyridine nitrogen doping enhance the oxygen reduction reaction electrocatalytic performance of metal-free laminated lignin-based carbon

Cu- and P-co-doped nitrogen-doped hierarchical carbon for enhanced oxygen reduction reaction in zinc-air batteries

High-performance Fe-based nitrogen-doped carbon oxygen reduction catalysts have been widely reported, but the Fenton reaction faced by such catalysts has hindered their practical application in fuel cells. The development of inexpensive, effective, and durable non-Fe nitrogen-doped carbon electrocatalysts is important for advancing fuel cell technology. In this work, we have introduced a molecular coordination chemistry method to synthesize a Cu- and P-co-doped nitrogen-doped hierarchical carbon (Cu-P-N-C) oxygen reduction reaction (ORR) electrocatalyst by pyrolyzing a mixture of phytate and melamine. The refined Cu-P-N-C material showcased a three-dimensional, porous, interconnected nanosheet structure with an ultra-high specific surface area and an abundance of active sites. The Cu-P-N-C catalyst displayed a half-wave potential (E1/2) of 0.86 VRHE, higher than that of commercial Pt/C in 0.1 M KOH. It was also found to maintain an impressive long-term stability, retaining 95.4% of its initial activity after extensive testing. When integrated into zinc-air batteries (ZABs), the Cu-P-N-C electrocatalyst was observed to deliver exceptional performance, achieving a high peak power density of 164.5 mW cm-2, a promising specific capacity of 807 mA h g-1, and remarkable stability. These findings underscore the potential of Cu-P-N-C as a potential candidate for next-generation ORR electrocatalysts in new energy devices.

Multi layered porous nitrogen-rich biochar materials derived from soybean cellulose for lithium metal anode three-dimensional skeleton in lithium batteries

Lithium metal, renowned for its ultra-high theoretical specific capacity and low electrochemical potential, is a promising anode material for high-energy-density batteries. However, its commercialization is impeded by issues such as uncontrolled Li dendrite growth and volumetric expansion during cycling. Herein, we report the synthesis of a nitrogen- and Si3N4-enriched porous based biochar derived from antibiotic mycelial residues rich in soybean cellulose, which serves as a three-dimensional skeleton for Li metal anodes. This biochar, characterized by a high specific surface area and a porous structure, along with its excellent electrical conductivity, facilitates uniform Li nucleation and growth, thereby mitigating dendrite formation. Results show that the biochar electrode after lithium deposition can achieve stable cycling for over 1200 h at a capacity of 2 mAh cm-2. When integrated with a NCM cathode in a coin cell configuration, the coin-type full cell demonstrates a capacity retention of 85.7 % after 300 cycles at a 0.3C rate. Additionally, pouch cell tests exhibit superior cycling stability with high-capacity retention. This study not only presents an innovative approach to the management of harmful biological waste high in soybean cellulose but also contributes to the advancement of Li metal anode materials for next-generation batteries.

Eco-Friendly Cellulose-Supported Nickel Complex as an Efficient and Recyclable Heterogeneous Catalyst for Suzuki Cross-Coupling Reaction

In this work, we applied commercially available 2-pyridinecarboxylic acid to modify cellulose by simple manipulations, and then anchored low-toxicity metal nickel onto the modified cellulose to prepare the heterogeneous catalyst (CL-AcPy-Ni). The obtained catalyst was characterized by FT-IR, TG-DSC, BET, XRD, SEM-EDS, ICP-OES, XPS, and GPC. The catalytic performance of CL-AcPy-Ni in the Suzuki cross-coupling reaction was investigated using 4-methyl iodobenzene and phenylboronic acid as the model substrates reacting in THF under 120 °C for 24 h. The catalytic ability of CL-AcPy-Ni for various halobenzenes and phenylboronic acid derivatives was also further investigated under optimal conditions and demonstrated good catalytic activity, and a series of diaryls were successfully synthesized. Finally, this green nickel-based catalyst could be reused for five successive cycles by simple centrifugation.

Biomass-Derived Catalytically Active Carbon Materials for the Air Electrode of Zn-Air Batteries

Given the growing environmental and energy problems, developing clean, renewable electrochemical energy storage devices is of great interest. Zn-air batteries (ZABs) have broad prospects in energy storage because of their high specific capacity and environmental friendliness. The unavailability of cheap air electrode materials and effective and stable oxygen electrocatalysts to catalyze air electrodes are main barriers to large-scale implementation of ZABs. Due to the abundant biomass resources, self-doped heteroatoms, and unique pore structure, biomass-derived catalytically active carbon materials (CACs) have great potential to prepare carbon-based catalysts and porous electrodes with excellent performance for ZABs. This paper reviews the research progress of biomass-derived CACs applied to ZABs air electrodes. Specifically, the principle of ZABs and the source and preparation method of biomass-derived CACs are introduced. To prepare efficient biomass-based oxygen electrocatalysts, heteroatom doping and metal modification were introduced to improve the efficiency and stability of carbon materials. Finally, the effects of electron transfer number and H2O2 yield in ORR on the performance of ZABs were evaluated. This review aims to deepen the understanding of the advantages and challenges of biomass-derived CACs in the air electrodes of ZABs, promote more comprehensive research on biomass resources, and accelerate the commercial application of ZABs.