Dechlorane Plus (DP) is a chlorinated flame retardant that is currently in intensive use and has been detected extensively in the environment. In China, the temporal and spatial distribution of DP is characterized by sources of point emissions in the south and diffusion to the north and west, including to remote, high-elevation areas, which are characterized by different climatic conditions and topographies. Thus, relatively high and low concentrations of DP have been observed in areas without significant nearby pollution sources. High DP concentrations have been observed in South China because of the recycling of large amounts of electronic waste and the presence of a DP factory. DP in urban areas is not influenced by atmospheric transportation, whereas DP in rural areas originates from atmospheric transmission from specific sources, such as e-waste recycling areas, which vary seasonally. Furthermore, DP in Chinese forest soils has been observed to preferentially accumulate in the mineral horizon due to leaching by precipitation as well as erosion by weathering in the organic horizon. Although the hazard quotient (HQ) has been estimated to be far from 1 for DP manufacturing operators, the HQ might not reveal deleterious effects on humans. Extremely high DP concentrations have been observed in serum samples from DP manufacturing operators in China. Moreover, different isomer-specific accumulation in terrestrial species, except for aquatic biota, shows that syn-DP is preferentially accumulated. Finally, to achieve better understanding of the mechanisms of DP degradation both in nature and in organisms, further laboratory study is needed.

4-Nitrophenol (4-NP) is a typical organic pollutant, thus it is urgent to detect it in environmental samples. This study rationally designed a novel electrode material of P-doping Fe/Fe ₃ O ₄ @C (P-Fe/Fe ₃ O ₄ @C) prepared with MIL-88 as precursor. P _2h -Fe/Fe ₃ O ₄ @C-700 was synthesized by calcining MIL-88 at 700 °C, followed by annealing process with NaH ₂ PO ₂ for 2 h. The P _2h -Fe/Fe ₃ O ₄ @C-700 modified glassy carbon electrode (P _2h -Fe/Fe ₃ O ₄ @C-700/GCE) showed a high electrocatalytic activity toward 4-NP reduction due to its active metal center, fine-tuned electronic structure by P-doping, as well as good electrical conductivity. It exhibited excellent sensing behaviors in 4-NP detection with rather high sensitivities of 1415.43 μ A·mM ⁻¹ ·cm ⁻² and 424.63 μ A·mM ⁻¹ ·cm ⁻² in the 4-NP concentration of 5 to 100 μ M and 100 to 1200 μ M, respectively, with a low detection limit of 0.462 μ M. The P _2h -Fe/Fe ₃ O ₄ @C-700/GCE still had good selectivity for 4-NP detection in the presence of common interferences. In addition, it was found that the current response towards 4-NP at P _2h -Fe/Fe ₃ O ₄ @C-700/GCE retained more than 97% of its initial value after one week, indicating a good long-term stability. Furthermore, the P _2h -Fe/Fe ₃ O ₄ @C-700/GCE exhibited a good reproducibility. The constructed P _2h -Fe/Fe ₃ O ₄ @C-700/GCE achieved practical uses for the sensing of 4-NP in tap water with satisfactory recoveries.

In this study, a SnO₂-carbon nanotube (SnO₂-CNT) composite as a catalyst for vanadium redox flow battery (VRFB) was prepared using a sol-gel method. The effects of this composite on the electrochemical performance of VO2+/VO²⁺, and on the V²⁺/V³⁺ redox reactions and VRFB performance were investigated. The SnO₂-CNT composite has better catalytic activity than pure SnO₂ and CNT due to the synergistic catalysis of SnO₂ and the CNT. SnO₂ mainly provides the catalytic active sites and the CNTs mainly provide the three-dimensional structure and high electrical conductivity. Therefore, the SnO₂-CNT composite has a larger specific surface area and an excellent synergistic catalytic performance. For cell performance, it was found that the SnO₂-CNT cell shows a greater discharge capacity and energy efficiency. In particular, at 150 mA cm⁻², the discharge capacity of the SnO₂-CNT cell is 28.6 mAh higher than that of the pristine cell. The energy efficiency of the modified cell (7%) is 7.2% higher than that of the pristine cell (62.8%). This study shows that the SnO₂-CNT is an efficient and promising catalyst for VRFB.