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A gas-penetrable electrode (GPE) composed of a Bi nanosheet array-wrapped Cu hollow fiber (Bi NSAs@Cu HF) is rationally designed and utilized for efficient electrocoupling of CO2 and N2 to produce urea with a yield of 79 μg h−1 cm−2, a faradaic efficiency (FEurea) of 6.8%, and excellent cycling stability at −0.2 V vs. reversible hydrogen electrode (RHE). [ABSTRACT FROM AUTHOR]

In pursuit of highly active zinc–air battery (ZAB) catalysts, nitrogen doping has proven key to enhancing carbon-based non-metallic catalysts' performance in the oxygen reduction reaction (ORR). This study employed a novel method to synthesize variously sized ZnO materials coated with ZIF-8. Notably, smaller particle sizes correlated with reduced activation energy. ZnO-12, the smallest variant, fully carbonized at 800 °C, resulting in zinc ion evaporation and the formation of an amorphous carbon nano-hollow structure, ZIF8/ZnO-12. This material showcased remarkable ORR properties, with an onset potential of 0.9 V (vs. RHE) and a Tafel slope of 71.4 mV dec−1, surpassing the benchmark Pt/C catalyst and exhibiting excellent stability. Moreover, in ZAB tests, ZIF8/ZnO-12 achieved a specific capacity of 816 mA h g−1, outperforming Pt/C. DFT calculations indicate that under alkaline conditions, nitrogen-doped carbon materials containing adsorbed oxygen and doped oxygen exhibit lower catalytic activation energy for the ORR, which is beneficial for accelerating the ORR. This research provides valuable insights into designing more efficient carbon-based non-metallic catalysts for ZABs. [ABSTRACT FROM AUTHOR]

A porous carbon‐based monolithic chainmail electrode, namely Co2P@CSA, is fabricated via direct carbonization of Co2+‐cross‐linked‐starch aerogel (Co2+‐SA) followed by low‐temperature vapor phosphorization. During successive carbonization‐phosphorization, the SA framework is formulated into 3D hierarchically porous carbon membrane matrix comprising hollow open carbon microspheres while the cross‐linked Co species are converted into uniformly distributed carbon‐encapsulated Co2P nanoparticles on carbon microspheres. Thanks to the high porosity, excellent electrolyte wettability, unique chainmail structure, and good mechanical strength, the monolithic Co2P@CSA can be directly used as a binder‐free bifunctional electrocatalyst for alkaline water splitting, and it can afford a high current density of 100 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at low overpotentials of 140.0 and 305.5 mV, respectively, with outstanding stability at 50 mA cm−2 for >30 h. More significantly, an alkaline electrolyzer assembled using Co2P@CSA achieves a current density of 100 mA cm−2 for overall water splitting (OWS) at a cell voltage of 1.94 V with unit Faradaic efficiency and provides a high solar‐to‐hydrogen (STH) conversion efficiency of 13.4 % when driven by a commercial silicon solar cell. This work offers an effective strategy towards cost‐effective fabrication of high‐performance carbon‐based monolithic chainmail electrocatalysts for energy conversion reactions. [ABSTRACT FROM AUTHOR]

Electrodes for commercially viable supercapacitors (SCs) require an active material mass loading of >10 mg cm−2; however, increasing the mass loading or electrode thickness typically deteriorates the electron and mass transfer and thus results in inferior specific capacitance, rate capability, and cycling stability. Herein, we develop a monolithic carbon membrane-based hybrid electrode (Co@CPE) with ultrahigh mass loading carbon-coated Co nanoparticles (>20 mg cm−2) by direct carbonization of Co2+-adsorbed Pleurotus eryngii (PE). During carbonization, the PE precursor is converted into a carbon membrane matrix with a layered porous structure, good conductivity and excellent structural integrity, whereas the adsorbed Co2+ ions are in situ converted into carbon-encapsulated Co nanoparticles that are firmly and evenly distributed on a carbon membrane matrix. The optimal Co@CPE-1000 electrode has a high areal capacitance of 5.04 F cm−2 at 2 mA cm−2. Due to the high mass loading, the symmetric SC assembled by the Co@CPE-1000 electrode has a high specific capacitance of 2.81 F cm−2 at 2 mA cm−2 and an energy density as high as 190 μW h cm−2. Notably, the symmetric SC exhibits an ultra-long cycle life, with a retention rate of 113% after 40 000 cycles. This work presents a feasible and effective strategy for the development of monolithic carbon membrane-based hybrid electrodes with high active mass loading for achieving practically viable SCs with excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

In this work, we develop a hierarchical carbon foam-based monolithic electrode (Co2P@HCF) from Co2+-adsorbed polyvinyl alcohol (PVA) sponge via the successive carbonization and phosphorization. Owing to the 3D hierarchical porous structure, excellent electrolyte wettability, good mechanical strength, and intimate embedding of highly dispersed Co2P nanoparticles, the Co2P@HCF electrode delivers a high current density of 1.0 A cm−2 for the hydrogen evolution reaction (HER) at ultralow overpotentials of 189.6 and 218.6 mV in 0.5 M H2SO4 and 1.0 M KOH solutions, respectively, with remarkable durability for 100 h. [ABSTRACT FROM AUTHOR]