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• A novel high-entropy electrocatalyst Ni 3 ZnC 0.7 @CoNiCuFe–NC has been fabricated. • Synergistic effect of multimetal, N, and C species improves catalytic activity. • This material exhibits outstanding catalytic performance for over water splitting. Due to unique electrical properties and high catalytic efficiency, transition metal nitrogen-codoped carbide (TM–N–C) has attracted tremendous interest as a multifunctional electrocatalyst for water splitting. Unlike traditional single-source modification, herein a novel pomegranate-like high-entropy (HE) electrocatalyst of Ni 3 ZnC 0.7 decorated with homogeneous multimetal (Fe, Co, Cu, and Ni) nitrogen-codoped carbon matrix (Ni 3 ZnC 0.7 @CoNiCuFe–NC) is reported. It can be implemented by the simple thermal annealing method of multimetal codoped zeolitic imidazolate framework (ZIF). Benefiting from the synergistic effects of plentiful TM–N–C species, template effect of ZIF and distinct nanoporous structure, HE electrocatalyst Ni 3 ZnC 0.7 @CoNiCuFe–NC exhibits outstanding electrocatalytic performance. When applied in strong alkaline electrolyte (1.0 M KOH), the overpotentials of Ni 3 ZnC 0.7 @CoNiCuFe–NC present as low as 202 and 97 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at 10 mA cm−2 current density. Surprisingly as a bifunctional electrode, it can achieve the low cell voltage of 1.53 V at 10 mA cm−2 current density for overall water splitting, which is comparable to conventional IrO 2 ||Pt/C electrode and superior to the recently reported analogous bifunctional catalysts. Thus, the work proposes the direction for the rational design of homogeneous distribution of TM–N–C material for water splitting in the green hydrogen energy industry. [ABSTRACT FROM AUTHOR]

Rechargeable Zn–air batteries have received extensive attention due to their use of nontoxic materials, safety, and high energy density. However, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air electrode of Zn–air batteries both suffer from slow kinetics, limiting their commercialization development. Herein, we prepared Co, N, and S co-doped hollow carbon nanoboxes (Co–N/S-CNBs) rich in topological defects using polyphenylene sulfide (PPS) as a sulfur-rich carbon source. Critically, by utilizing the self-propagating high-temperature synthesis (SHS), PPS can avoid melting, while simultaneously enabling the catalyst to take on a unique hollow structure. Additional post-treatment to introduce Co and N atoms as active centers further increases the defect sites and microporous structures of the catalyst. Under alkaline electrolytes, the Co–N/S-CNBs enabled Zn–air batteries to exhibit excellent bifunctional catalytic activity for both ORR and OER, surpassing commercial catalysts. Chemical analysis showed that the cracking loss of small molecules from PPS during pyrolysis is the main reason for the formation of topological defects, where the defect sites act as active centers to enhance the catalytic performance. Overall, this work provides new insights into the mechanism of how defects are formed in such a catalyst, as well as shows how a high-performance bifunctional electrocatalyst can be utilized for practical Zn–air batteries.

Hollow oxygen deficiency-enriched NiFe2O4@N/rGO serves as highly efficient bifunctional electrocatalysts for overall water splitting. The resultant NiFe2O4@N/rGO-800 exhibits excellent overall water splitting performance and good long-term stability.

(CF3C6H4)2SnO, (CH3C6H4)2SnO and Ph2SnO were successfully synthesized for the transesterification of DMC with BPA. The products of mono-methylcarbonate-ended-BPA (MmC(1)) and two-methylcarbonate-ended-BPA (DmC(1)) were selectively synthesized over them. The catalysts were characterized by FT-IR, TG and XPS. When Ph2SnO was used as the catalyst at 170 °C, the BPA conversion reached to 28.60% and the transesterification selectivity reached to 98.35%. As for (CF3C6H4)2SnO, BPA conversion and transesterification selectivity declined to 12.48% and 64.74%, respectively. The BPA conversion increased to 42.83%, but the transesterification selectivity declined to 44.55% over (CF3C6H4)2SnO. Notability, the higher transesterification selectivity of Ph2SnO was due to its lowest electron binding energy of Sn4+. More importantly, the DMC adsorption, activation and decomposition process over (CF3C6H4)2SnO, (CH3C6H4)2SnO and Ph2SnO were characterized by TG–MS and in situ DRIFT techniques, which provided more information about the mechanism of transesterification and methylation.

A green, environmentally friendly, and nontoxic method was developed to synthesize carboxylic anhydrides (NCAs) from γ-benzyl-l-glutamate (BLG) and dimethyl carbonate (DMC) though two steps: synthesis of N-methoxycarbonyl-γ-benzyl-l-glutamate intermediate (NOM-BLG) and cyclization. The highest yields of NOM-BLG (up to 83.7%) and NCA-BLG (up to 66.7%) were obtained. Most importantly, the use of DMC will open an innovative door to synthesize NCAs.

Polyphenylene sulfide (PPS) fiber products have been widely used for separation and filtration in harsh environments due to their excellent chemical resistance and relatively economical price. However, the poor temperature and weak oxidation resistance of PPS significantly shorten its service life under high temperature and strong oxidation environments. Herein, we report a type of oxidation-modified PPS (OPPS) fibers with excellent high temperature and oxidation resistance. This is achieved by oxidizing the thioether sulfide groups in PPS molecular chains into sulfoxide and sulfone groups and cross-linking the intermolecular chains. Both experiments and density functional theory (DFT) calculations indicate that hypochlorous acid (HClO) molecules can rapidly oxidize the PPS fiber surface. In addition, molecular dynamics (MD) simulations prove that there are strong hydrogen bonds and van der Waals interactions between HClO molecules and OPPS molecular chains, which promote the penetration of HClO molecules into the interior of the fiber to complete the layer-by-layer oxidation. The prepared OPPS-20 fibers exhibit excellent structural stability under high temperature and strong oxidant environments. Impressively, the OPPS-20 nonwoven filter still exhibits a high dust filtration efficiency of 99.95% after aging at 320 °C for 12 h, and the corresponding pressure drop is 24 Pa. In addition, the OPPS-20 nonwoven filter also maintains excellent filtration performance after aging in 60% HNO3solution for 12 h, and the filtration efficiency and pressure drop are 99.96% and 29 Pa, respectively. This work demonstrates that the novel OPPS fibers have excellent application prospects in the field of separation and filtration in harsh environments.