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Indoor formaldehyde poses a significant carcinogenic risk to human health, making its removal imperative. Electro-Fenton degradation has emerged as a promising technology for addressing this concern. In the electro-Fenton system, ·OH is identified as the primary active species responsible for formaldehyde removal. Hence, its generation and utilization are pivotal for the system's effectiveness and economy. Experimental and quantum chemical methods were employed to investigate the effects and mechanisms of nitrogen doping on various aspects influencing ·OH generation and utilization. Results indicate that nitrogen doping synergistically enhances the generation and utilization of ·OH, leading to an improved formaldehyde removal efficiency in nitrogen-doped cathodic systems. The dominant nitrogen type influencing ·OH generation and utilization varies across different stages. Pyridinic nitrogen facilitates H 2 O 2 adsorption through hydrogen bonding, while pyrrolic and graphitic nitrogen contribute to formaldehyde adsorption and catalyze the conversion of H 2 O 2 to ·OH. Both pyridinic nitrogen and pyrrolic nitrogen boost the degradation of formaldehyde by ·OH. In comparison to the unmodified system, the modified system with NAC-GF/700C as cathode exhibits remarkable improvements. The formaldehyde removal efficiency has increased twofold, and energy consumption reduced by 73.45%. Furthermore, the system demonstrates excellent cyclic stability. These advancements can be attributed to the activation temperature, which leads to the appropriate types and high content of nitrogen elements in NAC-GF/700C. The research represents an important step towards more economical and efficient electro-Fenton technology for indoor formaldehyde removal. [Display omitted] • The modified carbon cathode EF system achieves efficient degradation of indoor HCHO. • The type of N-doping significantly influences ·OH generation and utilization. • The activation temperature significantly affects the N species in carbon materials. [ABSTRACT FROM AUTHOR]

Investigating the impact of nitrogen doping on the selective adsorption of benzene on activated carbon under aqueous conditions holds significant importance in regulating nitrogen content on activated carbon precisely and enhancing benzene adsorption in the air. This study utilizes quantum chemical simulation to systematically compute the pairwise interactions of pyridine nitrogen, pyrrole nitrogen, graphite nitrogen, and their coexistence on carbon materials, including electrostatic potential, van der Waals potential, and polarity changes. We examine the adsorption of benzene and water on nitrogen-doped carbon materials and calculate the type and proportion of weak interactions in the adsorption process through energy decomposition analysis. Visual analysis of weak interactions is conducted via independent gradient scatter plots and isosurface plots. Based on this research, we investigate the influence of nitrogen doping on the competitive adsorption of benzene and water on carbon materials using adsorption energy and configuration changes. Our findings reveal that nitrogen doping disrupts the uniform electrostatic potential distribution and polarity of carbon materials. Specifically, graphite nitrogen inhibits water molecule adsorption by enhancing mutual repulsion and weakening dispersion and electrostatic interactions, consequently promoting benzene adsorption on carbon materials. Moreover, hydrogen bonds form between pyridine nitrogen, pyrrole nitrogen, and water, making carbon materials more hydrophilic. However, when combined with graphite nitrogen, this increases the negative van der Waals potential of carbon materials, further enhancing benzene adsorption. Experimental results align with the simulation, reinforcing the significance of this research in developing efficient activated carbon adsorbents for benzene under aqueous conditions. [Display omitted] • Nitrogen co-doping increases the negative van der Waals potential to improve the adsorption of C 6 H 6. • Graphite nitrogen improves the selective adsorption of C 6 H 6 on carbon through hydrophobic. • Pyridine and pyrrole nitrogen have synergistic effect on adsorption of C 6 H 6 with graphite nitrogen. [ABSTRACT FROM AUTHOR]

Phase change material (PCM) can effectively reduce temperature fluctuations in greenhouses and increase crop yields. Plastic greenhouses are a major form of facility agriculture in southern China, and there are no walls in it. Therefore, how to combine plastic greenhouses with PCM has become research hotspot. A new type of high absorption latent heat storage plate (LHSP) was proposed. That is to lay PCM plates on the north side of the plastic greenhouse vertically. To enhance solar energy utilization and reduce heat loss, solar high absorption and thermal insulation layer were respectively placed on the sunny side and shady side. Two greenhouses were constructed and LHSP was placed in one greenhouse as Case 1. After that, a solar high absorption film and thermal insulation layer were attached to the sunny side and the shady side as Case 2 and Case 3. The average air temperature of two greenhouses and the thermal performance of LHSP were compared under three cases. Results showed that, in Case 1, the LHSP can raise the average air temperature inside the greenhouse by 1.8–2.9 °C during the night. in Case 2 and 3, the average air temperature had a stable improvement of 1.6–2.2 °C and 1.8–2.1 °C respectively at night. Besides, in Case 2, the heat storage of LHSP on sunny side had increased by 26.2%. In Case 3, the total average heat loss of LHSP was reduced by 21.5% and the average heat release from sunny side had risen by up to 39.7%. The high absorption latent heat storage plate showed excellent thermal performance. [ABSTRACT FROM AUTHOR]