Upcycling of waste disposable medical masks to high value-added gasoline fuel and surfactants products by sub/supercritical water degradation and partial oxidation.

The amount of waste disposable medical masks (DMMs) and the potential environmental risk increased significantly due to the huge demand of disposable medical surgical masks. In this study, two effective and environmentally friendly processes, supercritical water degradation (SCWD) and subcritical water partial oxidation (SubCWPO), were proposed for the upcycling of DMMs. The optimal conditions for the SCWD process (conversion ratio>98 %) were 410 â„ƒ, 15 min, and 1:5 g/mL. The oil products obtained from the SCWD process were mainly small molecule hydrocarbons (C7-C12) with a content of 86 % and could be recycled as fuel feedstock for gasoline. Alkyl radicals in the SCWD reaction formed double bonds and ring structures through hydrogen capture reactions, ß-scission, and dehydrogenation reactions, and aromatic hydrocarbons were formed by olefin cyclization and cycloalkane dehydrogenation. The introduction of an oxidant (H2O2) to the reaction system could significantly reduce the reaction temperature and shorten the reaction time. At 350 â„ƒ, 15 min, 1:20 g/mL, V(H2O2): V (H2O) of 1:1, the conversion ratio of the SubCWPO process was 88 %, which was higher than that of the SCWD process at 400 â„ƒ (71.49 %). Oil products produced from the SubCWPO process were rich in alcohols and esters, which could be used as raw materials for nonionic surfactant of polyol and fatty acid ester. The abundant hydroxyl radical in the SubCWPO system trapped hydrogen atoms on PP and reacted with the resulting alkyl radical to form alkanols, which was oxidized to form acids. The esterification of acids and alkanols formed high level of esters. The SCWD and SubCWPO processes proposed in this study are believed to be promising strategies for DMMs degradation and the recovery of high value-added hydrocarbons.

Built-in Electric Field Promotes Interfacial Adsorption and Activation of CO2 for C1 Products over a Wide Potential Window.

The unsatisfactory adsorption and activation of CO2 suppress electrochemical reduction over a wide potential window. Herein, the built-in electric field (BIEF) at the CeO2/In2O3 n-n heterostructure realizes the C1 (CO and HCOO-) selectivity over 90.0% in a broad range of potentials from -0.7 to -1.1 V with a maximum value of 98.7 ± 0.3% at -0.8 V. In addition, the C1 current density (-1.1 V) of the CeO2/In2O3 heterostructure with a BIEF is about 2.0- and 3.2-fold that of In2O3 and a physically mixed sample, respectively. The experimental and theoretical calculation results indicate that the introduction of CeO2 triggered the charge redistribution and formed the BIEF at the interfaces, which enhanced the interfacial adsorption and activation of CO2 at low overpotentials. Furthermore, the promoting effect was also extended to CeO2/In2S3. This work gives a deep understanding of BIEF engineering for highly efficient CO2 electroreduction over a wide potential window.

Enhanced lithium polysulfide adsorption on an iron-oxide-modified separator for Li-S batteries.

Lithium-sulfur (Li-S) batteries are candidates for next-generation energy storage systems because of their low cost, high theoretical specific capacity and safety. However, the serious lithium polysulfide (LiPS) shuttle effect leads to a loss of reactive active substances and reduction of coulombic efficiency. In the current work, iron oxide (IO-700)-prepared by calcining a mixture of carbon spheres and ferric nitrate under an air atmosphere at 700 °C-was designed as a separator modifier to effectively adsorb LiPSs and accelerate the kinetics of the transformation of the intermediates, thereby inhibiting the shuttle effect. Li-S batteries including IO-700 showed long-term stability for 1000 cycles at 1C, with a capacity decay rate per cycle of only 0.0487%. A theoretical calculation indicated that, due to strongly polar active sites, Fe2O3 adsorbed LiPSs effectively to suppress the shuttle effect. This work has highlighted the importance for Li-S batteries of strongly polar active sites for anchoring LiPSs to inhibit the shuttle effect.

An alkali-enhanced subcritical water treatment strategy of short-chain chlorinated paraffins: Dechlorination and hydrocarbons recovery.

As persistent organic pollutants, short-chain chlorinated paraffins (SCCPs) have attracted wide attention in the field of environmental health risk and hazardous waste management. Efficient dechlorination of high content of SCCPs in plastic waste is the committed step for its detoxification and safety treatment. In this study, a high-efficiency and low-temperature process for dechlorination and hydrocarbons recovery from typical SCCPs (52#SCCPs) by subcritical water (SubCW) with alkali enhancer was developed. The introduction of alkali enhancer in the SubCW process had significantly enhanced effect on the dechlorination of 52#SCCPs, and the order of the enhanced effect of alkali enhancer for the dechlorination was NaOH > Na2CO3 > NaHCO3 > NH3·H2O > KOH. The dechlorination behaviors of 52#SCCPs in the NaOH-enhanced SubCW process were studied systematically under different conditions including temperature, residence time, alkali concentration, and volume ratio. The results showed that high-efficiency dechlorination (100 %) of 52#SCCPs could be achieved by the NaOH-enhanced SubCW process at low temperature for a short time (250 °C, 5 min). All of the chlorine released from the molecular chain of 52#SCCPs was transferred to the aqueous phase in the form of inorganic chlorine. The continuous HCl elimination reaction was the primary dechlorination mechanism for 52#SCCPs in the NaOH-enhanced SubCW process. After the dechlorination of 52#SCCPs, high value-added hydrocarbons such as 2,4-hexadiyne (31.74 %) could be obtained. The alkali-enhanced SubCW process proposed in this study is believed to be an environmentally friendly and high-efficiency method for dechlorination/detoxification and resource recovery of SCCPs.

Enhanced electron transfer by In doping in SnO2 for efficient CO2 electroreduction to C1 products.

Electrocatalytic CO2 reduction has received great attention for alleviating environmental problems and energy crisis. SnO2-based catalysts are attractive candidates, but they still face problems such as high overpotentials and small current density due to their low intrinsic electrical conductivity and weak activation for CO2. Here, superior selectivity and activity for C1 products (HCOO- and CO) were obtained using In-doped SnO2. The maximum faradaic efficiency was 96.46% at -0.75 V and the partial current density reached -20.12 mA cm-2 at -0.95 V for C1 products. Furthermore, the selectivity for C1 products was over 90% from -0.5 to -1.0 V with a current density of -166.2 mA cm-2 at -1.0 V in flow cells. In ion doping induced electron transfer from Sn species to In and simultaneously generated oxygen vacancies, which improved electrical conductivity and regulated the oxidation state of Sn active sites and provided more active sites. This work emphasizes the role of enhanced electron transfer of catalysts in CO2 electroreduction.

Bismuth with abundant defects for electrocatalytic CO2 reduction and Zn-CO2 batteries.

To regulate the electronic structure of Bi sites and enhance their intrinsic activity, metal Bi with abundant defects was constructed. The optimized sample displayed a higher selectivity (93.9% at -0.9 V) and a larger current density (-10 mA cm-2 at -1.0 V) towards electrocatalytic CO2 reduction to formate, which can be mainly attributed to abundant defect sites and the optimized electronic structure. The assembled Zn-CO2 batteries displayed a power density of 1.16 mW cm-2 and a cycling stability up to 22 h. This work deepens the research of Bi-based catalysts towards CO2 transformation and related energy devices.

Identification of a novel COL10A1: c.1952 G>T variant in a family with Schmid metaphyseal chondrodysplasia and development of a noninvasive prenatal testing method.

BACKGROUND: The collagen alpha-1(X) chain gene (COL10A1) is a known causative gene for Schmid metaphyseal chondrodysplasia (SMCD). This study clinically examined a Chinese family (n = 42) for SMCD and inheritance pattern. Fifteen individuals were diagnosed with SMCD based on characteristic skeletal phenotypes with autosomal dominant inheritance mode. METHODS: Four clinically diagnosed patients and three healthy relatives were selected for subsequent genetic tests. Trio-whole exome sequencing (Trio-WES) followed by Sanger sequencing and familial co-segregation analysis were performed to identify SMCD-associated variants. RESULTS: COL10A1 (NM_000493.4):c.1952 G>T(p.Trp651Leu) variant was detected only in the four patients and not in the three healthy relatives. The variant was evaluated as "likely pathogenic" according to the American College of Medical Genetics and Genomics variation classification guidelines with evidence of PM2, PM5, PP1, and PP3. To test the presence of the target variant in proband's fetal offspring, we developed a noninvasive prenatal testing method by extracting cell-free fetal DNA in maternal plasma followed by high-depth sequencing. The variant was also detected in the fetus and later confirmed by amniocentesis. CONCLUSION: We identified a new disease-causing variant in COL10A1. Cell-free fetal DNA in maternal peripheral blood can be used as the rapid and noninvasive prenatal diagnostic method to detect the pathogenic/or likely pathogenic variant.