An in-situ sol-gel method was used for the synthesis of boron-doped TiO₂-CNT nanocomposites with varied boron concentrations from 1 to 4 mol%. The synthesized nanocomposites were characterized by various techniques, namely XRD, UV-DRS, TEM, PL, and XPS; all results show that 3 mol% B-TiO₂-CNT nanocomposites have superior properties to pure TiO₂, 3B-TiO₂ nanoparticles, and other nanocomposites. TEM images clearly show the B-TiO₂ nanoparticles decorated on the CNT surface. Photo-luminescence studies confirm that boron doping of up to 3 mol% in TiO₂-CNT nanocomposites reduces the electron-hole pair recombination rate. The photocatalytic performance of the B-TiO₂-CNT nanocomposites was tested against the photodegradation of toluene gas and the photocatalytic inactivation of E. coli in the presence of UV and visible light respectively. B-TiO₂-CNT (3 mol%) nanocomposites show the highest photocatalytic activity.

In this study, Fe-doped graphitic carbon nitride (Fe-MCNC) with varying Fe contents was synthesized via a supramolecular approach, followed by thermal exfoliation, and was then used for accelerated photocatalytic hydrogen evolution and nitrogen fixation. Various techniques were used to study the physicochemical properties of the MCN (g-C₃N₄ from melamine) and Fe-MCNC (MCN for g-C₃N₄ and C for cyanuric acid) catalysts. The field emission scanning electron microscopy (FE-SEM) images clearly demonstrate that the morphology of Fe-MCNC changes from planar sheets to porous, partially twisted (partially developed nanotube and nanorod) nanostructures. The elemental mapping study confirms the uniform distribution of Fe on the MCNC surface. The X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance spectroscopy (UV-DRS) results suggest that the Fe species might exist in the Fe³⁺ state and form Fe-N bonds with N atoms, thereby extending the visible light absorption areas and decreasing the band gap of MCN. Furthermore, doping with precise amounts of Fe might induce exfoliation and increase the specific surface area, but excessive Fe could destroy the MCN structure. The optimized Fe-MCNC nanostructure had a specific surface area of 23.6 m² g⁻¹, which was 8.1 times greater than that of MCN (2.89 m² g⁻¹). To study its photocatalytic properties, the nanostructure was tested for photocatalytic hydrogen evolution and nitrogen fixation; 2Fe-MCNC shows the highest photocatalytic activity, which is approximately 13.3 times and 2.4 times better, respectively, than MCN-1H. Due to its high efficiency and stability, the Fe-MCNC nanostructure is a promising and ideal photocatalyst for a wide range of applications.

Ammonia, as the second most-produced chemical worldwide, serves diverse roles in the industrial and agricultural sectors. However, its conventional production via the Haber–Bosch process poses significant challenges, including high energy consumption and carbon dioxide emissions. In contrast, photocatalytic nitrogen (N₂) fixation, utilizing solar energy with minimal emissions, offers a promising method for sustainable ammonia synthesis. Despite ongoing efforts, photocatalytic nitrogen fixation catalysts continue to encounter challenges such as inadequate N₂ adsorption, limited light absorption, and rapid photocarrier recombination. This review explores how the electronic structure and surface characteristics of one-dimensional nanomaterials could mitigate these challenges, making them promising photocatalysts for N₂ fixation. The review delves into the underlying photocatalytic mechanisms of nitrogen fixation and various synthesis methods for one-dimensional nanomaterials. Additionally, it highlights the role of the high surface area of one-dimensional nanomaterials in enhancing photocatalytic performance. A comparative analysis of the photocatalytic nitrogen fixation capabilities of different one-dimensional nanomaterials is provided. Lastly, the review offers insights into potential future advancements in photocatalytic nitrogen fixation.

Nitrogen (N₂), constituting the majority of Earth’s atmosphere, remains indispensable for biological systems and underpins modern agriculture and industry. Traditionally, the Haber–Bosch process has been essential for synthesizing ammonia (NH₃) from N₂ under high temperature and pressure, but it contributes significantly to global CO₂ emissions. Recently, carbon-free electrocatalytic nitrogen reduction (e-NRR) has emerged as a promising, eco-friendly, and cost-effective approach for green NH₃ production under mild conditions using renewable energy, offering a sustainable alternative to the fossil fuel dependent Haber–Bosch process. This work explores NRR by contrasting the limitations of Haber–Bosch with the advantages of electrocatalysis. Despite progress, electrochemical N₂ reduction to NH₃ production remains challenging due to low activity, poor selectivity, stability, efficiency, and detection issues. Developing efficient e-NRR electrocatalysts is crucial to enhance activity, suppress hydrogen evolution reaction (HER), boost NH₃ yield, and improve Faradaic efficiency. This review highlights the role of layered double hydroxide (LDH) catalysts in e-NRR, summarizing the fundamental process, reaction pathways, and synthesis strategies. Ammonia detection methods, key metrics, and potential contamination issues are compared to inform standard NRR measurement protocols. Lastly, we summarize key findings to synthesize and improve LDH electrocatalysts for NH₃ production and a sustainable, carbon-free N₂ economy.

A simple biogenic synthetic route for the development of gold nanoparticles (Au NPs) from the fresh pods of Lablab purpureus was carried out. Further, Au NPs modified electrode employed for the selective sensing of dopamine. The stability, surface morphologies, microstructure and elemental compositions of the nanoparticles were probed by dynamic light scattering (DLS) with zeta potential, transmission electron microscopy (TEM), energy dispersive X-ray diffraction (EDX) and X-ray diffraction (XRD). The electrochemical features of dopamine at Au NPs modified glassy carbon electrodes (GCEs) was investigated in 0.1 M phosphate buffer solution (pH 7.4) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Gold nanoparticles modified GCEs in comparison with bare electrodes shows the significant catalytic activity towards dopamine from CV and DPV with limit of detection 5.9 nM and 7.7 nM, respectively. Additionally, the peak current response of dopamine does not interfered with the coexistence of ascorbic acid, uric acid and glucose.