ABSTRACT
A series of novel protic amino acid ionic liquids (PAAILs) are designed and synthesized for the first time through acid-base neutralization and an ion exchange reaction. Among the synthesised PAAILs, the [DBNH][Maba] PAAIL has the largest CO2 absorption capacity of 0.78 mol mol-1 (0.142 g g-1) at 313.2 K. The PAAILs are found to be efficient, reversible, and selective CO2 absorbents.
ABSTRACT
Groundwater environments are complex, and traditional advanced oxidation technologies mainly based on free radicals have limitations such as poor selectivity and low interference resistance, making it difficult to efficiently degrade target pollutants in groundwater. Therefore, we developed a sludge-based biochar-supported FeMg-layered double hydroxide catalyst (BC@FeMg-LDH) for the catalytic degradation of 2, 4-dichlorophenol (2, 4-DCP) using persulfate (PDS) as an oxidant. The removal efficiency of the catalyst exceeded 95%, showing high oxidation activity in a wide pH range while being almost unaffected by reducing substances and ions in the environment. Meanwhile, under neutral conditions, the leaching of metal ions from BC@FeMg-LDH was minimal, thereby eliminating the risk of secondary pollution. According to quenching experiments and electron paramagnetic resonance spectroscopy, the main active species during BC@FeMg-LDH/PDS degradation of 2, 4-DCP is 1O2, indicating a non-radical reaction mechanism dominated by 1O2. Characterization techniques, including X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, revealed that the carbonyl (C = O) and metal hydroxyl (M-OH) groups on the material surface were the main reactive sites mediating 1O2 generation. The 1O2 generation mechanism during the reaction involved ketone-like activation of carbonyl groups on the biochar surface and complexation of hydroxyl groups on the material surface with PDS, resulting in the formation of O2·- and further generation of 1O2. 1O2 exhibited high selectivity toward electron-rich organic compounds such as 2, 4-DCP and demonstrated strong interference resistance in complex groundwater environments. Therefore, BC@FeMg-LDH holds promising applications for the remediation of organic-contaminated groundwater.
Subject(s)
Groundwater , Hydroxides , Hydroxides/chemistry , Charcoal/chemistry , Metals , PhenolsABSTRACT
We present here a facile synthesis of SO2-4/ZrO2 solid superacid by impregnating the biscuit-like mesoporous ZrO2 nanoparticles prepared by an emulsion combustion method directly into H2SO4 solution. The obtained solid acid catalyst was characterized by means of X-ray powder diffraction, transmission and scanning electron microscopy, thermogravimetry, Brunner-Emmet-Teller measurement, and infrared analysis. Its catalytic performance was examined by alkylation of o-xylene with styrene. The optimal catalytic formulation, obtained from the investigation of experimental conditions, was determined to be 5 wt% of catalyst loading with initial o-xylene/styrene molar ratio of 5 under reaction temperature at 120 °C for 120 min, achieving a 100% styrene conversion and a 93.3% 1-phenyl-1-xylyl ethane selectivity. The biscuit-like SO2-4/ZrO2 solid acid exhibited high catalytic activity and selectivity and excellent structural stability. This synthetic strategy for preparing the mesoporous SO2-4 promoted ZrO2 solid superacid catalyst is generalized and expected to be applied to other metal oxides.
ABSTRACT
Biomass-derived carbons for supercapacitors provide a promising and sustainable strategy to address the worldwide energy and climate change challenges. Here, we have designed and constructed three-dimensional nitrogen/sulfur-codoped hierarchically porous carbons for high-performance supercapacitor electrode materials in a one-step process, in which ginkgo leaf is used as a carbon source and S source and ammonium nitrate (AN) is used as an activating agent and a N source. During the synchronous carbonization and activation process, AN could be decomposed completely into gaseous byproducts and be removed easily without leaving residues after product formation. The as-synthesized ginkgo leaf-derived carbons exhibited a high specific capacitance of 330.5 F g-1 at a current density of 0.5 A g-1 and a capacitance of 252 F g-1 even at a high current density of 10 A g-1 with an excellent capacitance retention of 85.8% after 10 000 cycles in 6 mol L-1 KOH electrolyte. The present study provides an efficient, sustainable, and facile approach to prepare renewable hierarchically porous carbons as advanced electrode materials for energy storage and conversion.
