Ammonia is one of the most useful chemicals for the fertilizer industry and is also promising as an important energy carrier for fuel cell application, and is currently mostly produced by the traditional Haber–Bosch process under high temperature and pressure conditions. This energy-intensive process is detrimental to the environment due to the dependence on fossil fuels and the emission of significant greenhouse gases (such as CO₂). Ammonia production via the electrochemical nitrogen reduction reaction (ENRR) has been recognized as a green sustainable alternative to the Haber–Bosch process in recent years. Current ENRR research mainly focuses on the catalyst for ammonia selective production and the enhancement of faradaic efficiency at high current density; however, these have not been explored well due to the unavailability of highly efficient and cheap catalysts. Herein, this review provides information on the ENRR process along with (i) theoretical background, (ii) experimental methodology of the electrocatalytic process and (iii) computational screening of promising catalysts. The impact of active sites and defects on the activity, selectivity, and stability of the catalysts is deeply understood. Furthermore, we demonstrate the mechanistic understanding of the ENRR process on the surface of catalysts, with the aim of boosting the improvement of the ENRR activities. The ammonia detection methods are also summarized along with thorough discussion of control experiments. Finally, this review highlights prevailing problems in existing ENRR methods of ammonia production along with technical advancements proposed to address these issues and concludes with comments on opportunities and future directions of the ENRR process.

Oil/water separation is a worldwide challenge and addressing this challenge calls for the development of efficient absorbent materials. Here a superhydrophobic/superoleophilic magnetic polyurethane (PU) sponge was fabricated via the facile dopamine self-polymerization to anchor Fe₃O₄ nanoparticles onto the skeleton of the PU sponge, followed by the introduction of low-surface-energy hydrophobic molecules heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane (FAS-17) on the sponge surface to induce the superhydrophobic transformation. The magnetic PU sponge displays excellent superhydrophobicity and superoleophilicity, and more favorably possesses magnetic responsiveness and superior stability against corrosive solutions; it gave outstanding separation performance under magnetic actuation not only for floating oils on the water surface and heavy organic pollutants under water, but also in the more complex environments such as an acidic solution (pH = 1) and simulated seawater, suggesting great potential in practical oily wastewater treatment. The presented approach provides a facile and easily scalable solution for the design and construction of multifunctional magnetic absorbent materials with low costs for practical applications in the petro-chemical field.

Photocatalytic TiO₂ coatings are famously known for their excellent self-cleaning behavior, where very thin water layer formed on the superhydrophilic surface can easily wash-off the dirt particles while flowing. Here we report the preparation of the optically transparent, adherent, highly wettable towards water and photocatalytic SiO₂-TiO₂ coatings on polycarbonate (PC) substrate for self-cleaning applications. The silica barrier layer was applied on UV-treated PC substrate before spin coating the SiO₂-TiO₂ coatings. The effect of different vol% of SiO₂ in TiO₂ and its influence on the surface morphology, mechanical stability, wettability, and photocatalytic properties of the coatings were studied in detail. The coatings prepared from 7 vol% of SiO₂ in TiO₂ showed smooth, crack-free surface morphology and low surface roughness compared to the coatings prepared from the higher vol% of SiO₂ in TiO₂. The water drops on this coating acquires a contact angle less than 10° after UV irradiation for 30 min. All the coatings prepared from different vol% (7 to 20) of SiO₂ in TiO₂ showed high transparency in the visible range.

A perovskite La₂Ti₂O₇nanosheet acts as an efficient electrocatalyst toward N₂-to-NH₃fixation, achieving a NH₃yield rate of 25.15 μg h⁻¹mg_cat.⁻¹and a faradaic efficiency of 4.55%.