Yu Bao

The upgrading of biomass into sustainable and valuable fine chemicals is an alternative to the use of state‐of‐the‐art petrochemicals. The conversion of 5‐hydroxymethylfurfural (HMF) biomass derivative into 2,5‐furandicarboxylic acid (FDCA) has been recognized as an economical and green approach to replace the current polyethylene terephthalate based plastic industry. However, this reaction mostly relies on noble‐metal‐based catalysts for the sluggish aerobic oxidation of alcohol groups. In this work, we report a series of hierarchical Ni−Co‐based transition metal oxide catalysts for HMF oxidation by electrocatalysis. Comprehensive material characterization and electrochemical evaluation have been performed. A 90 % FDCA yield, nearly 100 % Faradaic efficiency, and robust stability were achieved for NiCo₂O₄ nanowires. As non‐precious‐metal catalysts, Ni−Co‐based transition metal oxides may open up new potential materials for highly efficient electrochemical biomass upgrading.

Broad spectrum absorption of semiconductor photocatalysts is an essential requirement to achieve the best values of solar energy utilization. Here, through precise surface state adjustment, coaxial tri-cubic Ag⁰/AgCl materials with distinct apparent colours (blue and fuchsia) were successfully fabricated. The reasons for the different colour generation of the Ag⁰/AgCl materials were investigated by performing corresponding spectrum analysis. It was revealed that Ag⁰/AgCl-blue and Ag⁰/AgCl-fuchsia crystals could efficiently boost the photon energy harvesting, spanning from the UV to near-infrared spectral region (250–800 nm), and achieved 2.6 and 5.4 times the wastewater degradation efficiency of AgCl-white. Simultaneously, these two fresh coloured candidates were demonstrated to have preferable photocatalytic CO₂ photoreduction capability, with yields of ∼3.6 (Ag⁰/AgCl-fuchsia) and 2.6 (Ag⁰/AgCl-blue) times that of AgCl-white. It is expected that this work will provide a beneficial perspective for understanding the solar absorption feature at both the major structure modulation and particular surface state regulation level.

The high cost and limited natural abundance of platinum hinder its widespread applications as the oxygen reduction reaction (ORR) electrocatalyst for fuel cells. Carbon-supported materials containing metals such as Fe or Co as well as nitrogen have been proposed to reduce the cost without obvious lowering the performance compared to Pt-based electrocatalysts. In this work, based on the pyrolyzed corrin structure of vitamin B12 on the simultaneously reduced graphene support (g-VB12), we construct an efficient oxygen reduction electrocatalyst with very positive half-wave potential (only ∼30 mV deviation from Pt/C), high selectivity (electron transfer number close to 4) and excellent durability (only 11 mV shift of the half-wave potential after 10 000 potential cycles). The admirable performance of this electrocatalyst can be attributed to the homogeneous distribution of abundant Co–N_x active sites, and a well-defined three-dimensional mesoporous structure of the N-doped graphene support. The high activity and long-term stability of the low cost g-VB12 make it a promising ORR electrocatalyst in alkaline fuel cells.