Alcoholysis is one of the most effective methods for recycling polyester plastics.While many researchers claim that both alcohol and polymer reactants are activated simultaneously in the alcoholysis reaction,more reli...Alcoholysis is one of the most effective methods for recycling polyester plastics.While many researchers claim that both alcohol and polymer reactants are activated simultaneously in the alcoholysis reaction,more reliable experimental evidence is needed to fully understand the process,and the catalytic mechanism remains elusive.To address this issue,we proposed a reactant-modulated catalytic depolymerization strategy involving a pre-mixing of alcohol or polylactic acid(PLA)with an organic base catalyst.Through systematic experimental and theoretical investigations,we have confirmed that different intermediates are formed during pre-mixing the catalyst with PLA or methanol,which can either slow down or accelerate the subsequent alcoholysis reaction.By employing the methanol-modulated depolymerization technique,we successfully achieved PLA alcoholysis at temperatures as low as–40℃.We further investigated the solubility and reactivity of different polyesters,including PET,PC,PBS,PBAT,PCL,and PLA,revealing an efficient recycling method for PLA.By optimizing reaction conditions in a continuous flow reactor,we recovered 127.3 g of methyl lactate from 100 g of plastic cups in just 4 h at room temperature.These findings greatly improve our grasp of polyester solvolysis processes and create new opportunities within the plastics sector recycling.展开更多
The escalating challenge of phosphorus pollution demands innovative solutions for efficient phosphate removal and recovery.Herein,a three-dimensional heterostructured C-ZIF@LDH/CF anode was constructed for capacitive ...The escalating challenge of phosphorus pollution demands innovative solutions for efficient phosphate removal and recovery.Herein,a three-dimensional heterostructured C-ZIF@LDH/CF anode was constructed for capacitive deionization(CDI)by in-situ growing NiCo-layered double hydroxide(LDH)nanoflowers on a carbonized Co-ZIF-L framework anchored onto carbon fiber cloth(CF).This architecture synergistically integrates hierarchical porosity,dual-mode capacitive mechanisms of electrical doublelayer and Faradaic pseudocapacitance,and robust interracial charge transfer pathways.Comprehensive physicochemical characterizations validated the morphological evolution and synergistic valence modulation of metallic species.Electrochemical evaluations revealed outstanding phosphate removal performance,achieving a record adsorption capacity of 34.96 cmp/g in 50 mg_P/L solution,along with superior kinetic efficiency(0.21 mgp/g/min)in hybrid CDI(HCDI)operation.The heterojunction design ensures 95.71%capacity retention over 50 cycles and exceptional selectivity against competing anions.Molecular dynamics(MD)simulations further validate the confinement effect of LDH layers,demonstrating preferential phosphate adsorption through hydrogen bonding and restricted ion mobility.Density functional theory(DFT)calculations elucidate that the ZIF-derived carbon framework enhances conductivity through Co-C hybridization,while simultaneously revealing a reduced work function and a significantly stronger phosphate adsorption energy compared to pristine NiCo-LDH,underpinning enhanced electron transfer and chemisorption.This work provides a paradigm for advanced CDI systems,bridging structural engineering with atomic-scale mechanistic insights to address water-energy-resource challenges.展开更多
文摘Alcoholysis is one of the most effective methods for recycling polyester plastics.While many researchers claim that both alcohol and polymer reactants are activated simultaneously in the alcoholysis reaction,more reliable experimental evidence is needed to fully understand the process,and the catalytic mechanism remains elusive.To address this issue,we proposed a reactant-modulated catalytic depolymerization strategy involving a pre-mixing of alcohol or polylactic acid(PLA)with an organic base catalyst.Through systematic experimental and theoretical investigations,we have confirmed that different intermediates are formed during pre-mixing the catalyst with PLA or methanol,which can either slow down or accelerate the subsequent alcoholysis reaction.By employing the methanol-modulated depolymerization technique,we successfully achieved PLA alcoholysis at temperatures as low as–40℃.We further investigated the solubility and reactivity of different polyesters,including PET,PC,PBS,PBAT,PCL,and PLA,revealing an efficient recycling method for PLA.By optimizing reaction conditions in a continuous flow reactor,we recovered 127.3 g of methyl lactate from 100 g of plastic cups in just 4 h at room temperature.These findings greatly improve our grasp of polyester solvolysis processes and create new opportunities within the plastics sector recycling.
基金financially supported by the National Natural Science Foundation of China[No.52072180]supported by the Key Research and Development Program of China(2023YFC3904101)+1 种基金the Tai Shan Industrial Experts Programme(NO.tscx.202408047)the Urgently Needed Talent Introduction Projects of Key support areas of Shandong Province(2204370402-04-01-608853416)。
文摘The escalating challenge of phosphorus pollution demands innovative solutions for efficient phosphate removal and recovery.Herein,a three-dimensional heterostructured C-ZIF@LDH/CF anode was constructed for capacitive deionization(CDI)by in-situ growing NiCo-layered double hydroxide(LDH)nanoflowers on a carbonized Co-ZIF-L framework anchored onto carbon fiber cloth(CF).This architecture synergistically integrates hierarchical porosity,dual-mode capacitive mechanisms of electrical doublelayer and Faradaic pseudocapacitance,and robust interracial charge transfer pathways.Comprehensive physicochemical characterizations validated the morphological evolution and synergistic valence modulation of metallic species.Electrochemical evaluations revealed outstanding phosphate removal performance,achieving a record adsorption capacity of 34.96 cmp/g in 50 mg_P/L solution,along with superior kinetic efficiency(0.21 mgp/g/min)in hybrid CDI(HCDI)operation.The heterojunction design ensures 95.71%capacity retention over 50 cycles and exceptional selectivity against competing anions.Molecular dynamics(MD)simulations further validate the confinement effect of LDH layers,demonstrating preferential phosphate adsorption through hydrogen bonding and restricted ion mobility.Density functional theory(DFT)calculations elucidate that the ZIF-derived carbon framework enhances conductivity through Co-C hybridization,while simultaneously revealing a reduced work function and a significantly stronger phosphate adsorption energy compared to pristine NiCo-LDH,underpinning enhanced electron transfer and chemisorption.This work provides a paradigm for advanced CDI systems,bridging structural engineering with atomic-scale mechanistic insights to address water-energy-resource challenges.
