Porous carbon-nanostructured electrocatalysts for zinc-air batteries: from materials design to applications.

Zinc-air batteries (ZABs) are pivotal in the evolution of sustainable energy storage solutions, distinguished by their high energy density and minimal environmental footprint. The oxygen electrode, which relies on sophisticated porous carbon materials, is critical to operational efficiency. This review scrutinizes oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes in ZABs through advanced porous carbon applications.

Se-Doped CoS@MoS Heterostructures on Multiwalled Carbon Nanotubes as Efficient Bifunctional Electrocatalysts for Alkaline Overall Water Splitting.

The use of efficient and affordable non-precious metal catalysts for hydrogen and oxygen evolution reactions is vital for replacing and widely implementing new energy sources. Nevertheless, improving the catalytic performance of these non-precious-metal bifunctional electrocatalysts continues to be a major challenge. In this article, an optimized Se-incorporated bulk CoS@MoS heterostructure grown on the surface of carbon nanotubes is reported.

Self-supported iron-doped cobalt-copper oxide heterostructures for efficient electrocatalytic denitrification.

The electrocatalytic reduction of nitrate ions (NO) to nitrogen gas (N) has emerged as an effective approach for mitigating nitrate pollution in water bodies. However, the development of efficient and highly selective cathode materials remains challenging. Conventional copper-based catalysts often exhibit low selectivity because they strongly adsorb oxygen.

Recent Advances in Catalyst Design and Performance Optimization of Nanostructured Cathode Materials in Zinc-Air Batteries.

This review focuses on the advanced design and optimization of nanostructured zinc-air batteries (ZABs), with the aim of boosting their energy storage and conversion capabilities. The findings show that ZABs favor porous nanostructures owing to their large surface area, and this enhances the battery capacity, catalytic activity, and life cycle. In addition, the nanomaterials improve the electrical conductivity, ion transport, and overall battery stability, which crucially reduces dendrite growth on the zinc anodes and improves cycle life and energy efficiency.

Recent advances in alginate-based composite gel spheres for removal of heavy metals.

The discharge of heavy metal ions from industrial wastewater into natural water bodies is a consequence of global industrialisation. Due to their high toxicity and resistance to degradation, these heavy metal ions pose a substantial threat to human health as they accumulate and amplify. Alginate-based composite gels exhibit good adsorption and mechanical properties, excellent biodegradability, and non-toxicity, making them environmentally friendly heavy metal ion adsorbents for water with promising development prospects.

Co Nanoparticles Confined in Mesoporous Mo/N Co-Doped Polyhedral Carbon Frameworks towards High-Efficiency Oxygen Reduction.

Exploiting effective non-noble metal electrocatalysts for oxygen reduction reaction (ORR) is crucial for fuel cells and metal-air batteries. Herein, we designed and fabricated Co nanoparticles confined in Mo/N co-doped polyhedral carbon frameworks (Co-NP/MNCF) derived from polyoxometalate-encapsuled metal-organic framework, which showed comparable ORR performance with commercial Pt/C and a larger diffusion-limited current density. Moreover, the Co-NP/MNCF also exhibited excellent ORR stability and methanol tolerance.

Nitrogen-Doped Carbon Polyhedrons Confined Fe-P Nanocrystals as High-Efficiency Bifunctional Catalysts for Aqueous Zn-CO Batteries.

Emerging Fe bonded with heteroatom P in carbon matrix (FePC) holds great promise for electrochemical catalysis, but the design of highly active and cost-efficient FePC structure for the electrocatalytic CO reduction reaction (CO RR) and aqueous ZnCO batteries (ZCBs) is still challenging. Herein, polyhedron-shaped bifunctional electrocatalysts, FeP nanocrystals anchored in N-doped carbon polyhedrons (Fe-P@NCPs), toward a reversible aqueous ZnCO battery, are reported. The Fe-P@NCPs are synthesized through a facile strategy by using self-templated zeolitic imidazolate frameworks (ZIFs), followed by an in situ high-temperature calcination.

Metal-Free Bifunctional Ordered Mesoporous Carbon for Reversible Zn-CO Batteries.

The fabrication of Zn-CO batteries is a promising technique for CO fixation and energy storage. Herein, nitrogen-doped ordered mesoporous carbon (NOMC) is adopted as a bifunctional metal-free electrocatalyst for CO reduction and oxygen evolution reaction in the near-neutral electrolyte. The ordered mesoporous structures and abundant N-dopings of NOMC facilitate the accessibility and utilization of the active sites, which endow NOMC with excellent electrocatalysis performance and outstanding stability.

Single-unit-cell-thick layered electrocatalysts: from synthesis to application.

Electrocatalysts are critical for water splitting, carbon dioxide reduction, and zinc-air battery. However, the low-exposed surface areas of bulk electrocatalysts usually limit the complete utilization of active sites. Ultrathin electrocatalysts have noteworthy advantages in maximizing the use of active sites.

A Facile Electrochemical Sensor Based on PyTS⁻CNTs for Simultaneous Determination of Cadmium and Lead Ions.

A simple and easy method was implemented for the contemporary detection of cadmium (Cd) and lead (Pb) ions using 1,3,6,8-pyrenetetrasulfonic acid sodium salt-functionalized carbon nanotubes nanocomposites (PyTS⁻CNTs). The morphology and composition of the obtained PyTS⁻CNTs were characterized using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS). The experimental results confirmed that the fabricated PyTS⁻CNTs exhibited good selectivity and sensitivity for metal ion-sensing owing to the insertion of sulfonic acid groups.

Selective voltammetric determination of Cd(II) by using N,S-codoped porous carbon nanofibers.

Porous carbon nanofibers codoped with nitrogen and sulfur (NFs) were prepared by pyrolysis of trithiocyanuric acid, silica nanospheres and polyacrylonitrile (PAN) followed by electrospinning. The NFs were used to modify a glassy carbon electrode (GCE) which then displayed highly sensitive response to traces of Cd(II). Compared to a bare GCE and a Nafion modified GCE, the GCE modified with codoped NFs shows improved sensitivity for Cd(II) in differential pulse anodic sweep voltammetry.

Synergistic Effects between Atomically Dispersed Fe-N-C and C-S-C for the Oxygen Reduction Reaction in Acidic Media.

Various advanced catalysts based on sulfur-doped Fe/N/C materials have recently been designed for the oxygen reduction reaction (ORR); however, the enhanced activity is still controversial and usually attributed to differences in the surface area, improved conductivity, or uncertain synergistic effects. Herein, a sulfur-doped Fe/N/C catalyst (denoted as Fe/SNC) was obtained by a template-sacrificing method. The incorporated sulfur gives a thiophene-like structure (C-S-C), reduces the electron localization around the Fe centers, improves the interaction with oxygenated species, and therefore facilitates the complete 4 e ORR in acidic solution.