ABSTRACT Enhancing the efficiency of bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for sustainable water splitting. In this study, the electrochemical performance of Cu‐doped mixed spinel cobalt ferrites (CuCoFe) was systematically investigated, focusing on the role of oxygen vacancies in catalytic activity. Cu doping optimized charge transfer modulated the electronic structure and promoted oxygen vacancy formation, collectively enhancing reaction kinetics. Among the synthesized materials, CuCoFe0.5 exhibited the lowest overpotential, with 280 mV for OER and −143 mV for HER, alongside a cell voltage of 1.66 V during 20 h of continuous water splitting. The appreciable catalytic performance of CuCoFe0.5 was attributed to its enhanced electrochemically active surface area (ECSA) and abundant oxygen vacancies, which serve as active sites for HER and OER. Furthermore, its long‐term stability highlights its potential as a durable electrocatalyst. The electrochemical performance forecasting (30%) was done using LSTM memory cell. Overall, study underscores the critical role of oxygen vacancies in improving catalytic efficiency, offering valuable insights for designing next‐generation spinel ferrite‐based electrocatalysts for water splitting.

Metal–organic frameworks (MOFs) have recently garnered immense attention for their applications in the oxygen evolution reaction (OER) during electrochemical water splitting, owing to their exceptional characteristics such as high specific surface area (SSA), abundant and regular porosity, and flexibility in their framework, dimension, geometry, and functionality of metal active sites. It is speculated that the incorporation of additional transition metals into the MOF network effectively enhances the material’s electrocatalytic activities. In this study, we synthesized a bimetallic CoFeBTC MOF with an SSA of 310.59 m2g–1 using a simple, inexpensive one-step solvothermal approach and employed it for OER applications. The CoFeBTC MOF demonstrated superior electrocatalytic activity, achieving an overpotential of 310 mV at 10 mA cm–2 and a Tafel slope of 122 mV dec–1 in an alkaline medium (1 M KOH) electrolyte. Notably, the synergistic interaction between cobalt (Co) and iron (Fe) in the bimetallic framework significantly boosts the electrochemical activity toward the OER compared to individual CoBTC and FeBTC MOFs. This solvothermal technology and its synergistic effect may encourage researchers to explore and develop more reliable and efficient electrocatalysts for energy conversion.

• The upcycling of polymeric waste to nanoporous activated carbon for potential CO 2 capture. • Engineering the pores and surface functionality by chemical carbonization followed by activation. • The ultra-micro porosity, C-O and C-N functionality ascribed due to 1:2 KOH impregnation contributing maximum CO 2 capture. • The proposed framework offers tuning of the desired attributes of nanoporous activated carbon for CO 2 capture. The efficient CO 2 capture requires engineering a low-cost, highly efficient adsorbent. Herein, the upcycling of waste floral foam into chemically activated nanoporous carbon (CANC) is reported. The implications of the impregnation ratio of KOH on the porosity, surface functionality of CANC, and its role in CO 2 capture are examined and discussed. The optimized sample, CANC-2 (SSA 1043 m 2 /g), with a large ultra-micropore volume and higher oxygen and nitrogen content, demonstrates 3.71 mmol/g CO 2 capture capacity at 15 ℃ and 1 atm. The framework provided here offers a technique for tuning the attributes of nanoporous carbon favorable for CO 2 capture. Ultimately, the pollution control of solid polymeric waste can be done by upcycling it into value-added products which further utilized in environmental applications.

The NiO/FeS@CNT hybrid achieves low overpotentials and favorable Tafel slopes for the HER and OER in KOH media. Notably, the electrolytic cell operates at an exceptionally low voltage of 1.465 V, which is significantly lower than various literature.

ABSTRACT Enhancing the efficiency of bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for sustainable water splitting. In this study, the electrochemical performance of Cu‐doped mixed spinel cobalt ferrites (CuCoFe) was systematically investigated, focusing on the role of oxygen vacancies in catalytic activity. Cu doping optimized charge transfer modulated the electronic structure and promoted oxygen vacancy formation, collectively enhancing reaction kinetics. Among the synthesized materials, CuCoFe0.5 exhibited the lowest overpotential, with 280 mV for OER and −143 mV for HER, alongside a cell voltage of 1.66 V during 20 h of continuous water splitting. The appreciable catalytic performance of CuCoFe0.5 was attributed to its enhanced electrochemically active surface area (ECSA) and abundant oxygen vacancies, which serve as active sites for HER and OER. Furthermore, its long‐term stability highlights its potential as a durable electrocatalyst. The electrochemical performance forecasting (30%) was done using LSTM memory cell. Overall, study underscores the critical role of oxygen vacancies in improving catalytic efficiency, offering valuable insights for designing next‐generation spinel ferrite‐based electrocatalysts for water splitting.