The traditional synthesis of ammonia is an industrial process with high energy consumption that is not environmentally friendly; thus, it is urgent to develop cost-effective approaches to synthesize ammonia under ambient conditions.

A PPy/TiO₂ nanocomposite coating was fabricated by direct electropolymerization of pyrrole on annealed TiO₂ nanoparticles and evaluated as a novel direct immersion solid phase microextraction fiber coating for the extraction of trace pollutants in water.

The removal of Pb2+ in the aqueous solutions by adsorption onto insolubilized humic acid (IHA) is investigated. The equilibrium isotherms were determined at pH 3.5 under constant ionic strength and at different temperatures. At the same time, the paper has also analyzed the adsorption experimental data by using three different isotherm models: Langmuir, Frendlich and Linear isotherm. As the result, it has obtained the optimal correlation for Frendlich isotherm equations. In addition, the paper has calculated the thermodynamic quantities ΔH in accordance with the Clausius-Claperyon,s theory. It means that the type of adsorption of Pb2+ onto IHA is physisorption, rather than by chemical bonding. And finally, the adsorption equilibrium gained around 12 hours and a high and stable removal of heavy metals on insoluble humic acid has been obtained almost under the neutral conditions.

Bismuth oxyiodide and attapulgite have proven to be potential materials for the removal of emerging contaminants in wastewater.

A novel titanium dioxide nanotube (TiO₂NTS) coated fiber for solid-phase microextraction (SPME) was prepared by in situ anodization of titanium wire in electrolyte containing ethylene glycol and ammonium fluoride (NH₄F). The effects of different electrolyte solutions (NH₄F and ethylene glycol) and oxidation voltages on the formation and size of TiO₂NTs was studied. It was obtained from the experiment that TiO₂NTs arrays were arranged with a wall thickness of 25 nm and the diameter of 100 nm pores in ethylene glycol and water (v/v, 1:1) containing NH₄F of 0.5% (w/v) with a voltage of 20 V at 25 °C for 30 min. The TiO₂NTs were used as solid-phase microextraction fiber coatings coupled with high-performance liquid chromatography (HPLC) in sensitive determination of polycyclic aromatic hydrocarbons (PAHs) in spiked real samples water. Under the optimized SPME conditions, the calibration curve has good linearity in the range of 0.20–500 μg·L⁻¹, and the correlation coefficient (R²) is between 0.9980 and 0.9991. Relative standard deviations (RSDs) of 3.5–4.7% (n = 5) for single fiber repeatability and of 5.2% to 7.9% for fiber-to-fiber reproducibility (n = 3) was obtained. The limits of detection (LOD) (S/N = 3) and limits of quantification (LOQ) (S/N = 10) of PAHs were 0.03–0.05 µg·L⁻¹ and 0.12–0.18 µg·L⁻¹. The developed method was applied to the preconcentration and determination of trace PAHs in spiked real samples of water with good recoveries from 78.6% to 119% and RSDs from 4.3 to 8.9%, respectively.

The prepared porous polyimide served as a cathode for LIBs, and delivers a high discharge platform of 2.1 V and satisfactory electrochemical performance.