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A porous organic framework containing well‐defined donor–acceptor units, named donor–acceptor porous organic framework (D–A‐POF), is successfully synthesized. The localized electric field gradient at the pore surface induced by the intramolecular donor–acceptor (D–A) interactions endows D–A‐POF with excellent desulfurization capabilities. D–A‐POF exhibits high adsorption capacity of 3‐methylthiophene (12.26 mmol g−1, 392.32 mg S g−1) and 1‐benzothiophene (793.65 mg g−1, 189.25 mg S g−1) with impressive adsorption selectivity. Density functional theory calculations provide compelling evidence of the preferential selective adsorption of aromatic thiophene sulfides in D–A‐POF. In fixed‐bed breakthrough experiments, D–A‐POF demonstrates its ability to selectively capture thiophene sulfides from model gasoline, resulting in fuel with sulfide content below 10 ppb. The high stability and high desulfurization efficiency of D–A‐POF make it promising as a new porous adsorbent for ultra‐depth adsorption desulfurization. [ABSTRACT FROM AUTHOR]

Efficient and inherently safe NH3 storage and separation are of significant importance for the chemical industry. Herein, we proposed zwitterionic COF as a porous host to disperse LiCl for highly efficient NH3 storage and separation with record adsorption capacity. The equivalently cationic and anionic groups in the channels of zwitterionic COF could act as two separated sites to facilitate the dispersion of LiCl, hence the optimal composite exhibits a high capture capacity of 44.98 mmol/g at 25 °C and 1 bar, far exceeding other existing porous materials. Notably, the adsorption capacity is completely reversible and the efficient separation of NH3 from NH3/CO2/N2 mixture is achieved through breakthrough experiments. DFT calculation combined with XPS and 7Li NMR experimental results give insight into the interaction between zwitterionic COF and LiCl. This work extends possibilities for the development of efficient adsorbents for NH3 storage and separation. [ABSTRACT FROM AUTHOR]

• Humidity sensor based on sulfonate-based COF is fabricated. • 2D sulfonate-based COF possesses superior water adsorption capacity (∼396 mg/g). • COF's 1D pore can provide continuous proton/ions conducting channel. Sensing material is crucial to the performance of humidity sensors. Porous material is widely used for humidity sensing but suffers from the narrow detecting range and slow response speed. Herein, the porous TpBDSA-Na COF with a large pore size (∼1.7 nm) and high density of hydrophilic active sites is used as sensing material for humidity detector. The superior adsorption capacity of water molecules (∼396 mg/g) in TpBDSA-Na COF makes the humidity detector exhibit fast response speed (18/9 s), small hysteresis (∼3% RH) and long-term stability (∼20 days) in 11%–95% RH range. Moreover, the sensing mechanism of TpBDSA-Na sensor is also discussed in detail. This research indicates the 2D COF with a hydrophilic channel can be used as a promising material for humidity sensing. [ABSTRACT FROM AUTHOR]

• Ionic covalent organic framework (COF) named TpPa-SO 3 Na was successfully fabricated into humidity sensor for the first time. • The sensor presents good linearity, rapid response characteristic, narrow hysteresis and excellent long-term stability. • The TpPa-SO 3 Na with self-provided ion carriers plays an important role in improving the conductivity in periodic pore structure. With the increasing requirement of precise humidity control in agriculture, industry, and scientific experiments, the humidity sensors based on porous materials such as metal-organic framework (MOF) have aroused much attention because of their high porosity and tunable structure. However, the reported MOFs exhibit narrow detecting range and long response time due to the absence of ion carriers in porous framework. In this paper, an ionic covalent organic framework (COF) named TpPa-SO 3 Na was synthesized, and its humidity sensing performance was investigated for the first time. TpPa-SO 3 Na with -SO 3 Na groups possesses a water adsorption capacity of 411 cm3 g−1, which is confirmed by water adsorption-desorption measurement. The sensor based on TpPa-SO 3 Na exhibits good impedance-RH linearity, rapid response characteristic (∼6 s) and narrow hysteresis (∼3% RH) in the 11–95 % RH. Moreover, the ionic COF sensing material presents good repeatability. These results strongly suggest ionic COFs are a class of promising candidates for humidity sensing applications. [ABSTRACT FROM AUTHOR]

Adsorption can effectively remove recalcitrant micro-pollutants in wastewater. However, its industrial application is constrained by the adsorption saturation. This work introduces a novel technique to directly immobilize the laccases onto the CNTs (Laccase-Carbon nanotubes) to improve its adsorption performance. Comprehensive investigations were carried out to compare and understand the adsorption performance at various operational conditions for Carbon nanotube and Laccase-Carbon nanotubes. By calculating the adsorption thermodynamics, adsorption kinetics and particle diffusion kinetics, the removal improvement mechanisms were revealed. The results showed that Laccase-Carbon nanotubes performed much better regarding the dye removal rate (96% within 3 h) and better stability than Carbon nanotubes (84% within 3 h), under various operating conditions (carbon nanotube concentration (0.02–0.08 g/L), laccase ratio (0.25–1.25), dye concentration (10–60 mg/L), temperature (15–35 °C), and rotating speed (0–250 rpm)). Besides, the isothermal adsorption model and adsorption kinetic indicated that Laccase-carbon nanotubes possessed greater adsorption capacity than carbon nanotubes, which may maybe due to the fact that adsorbed dyes onto carbon nanotubes were timely eliminated by laccases, achieving regeneration of adsorption capacity. Moreover, based on the particle diffusion kinetic, the diffusion rate of dyes onto the surface or into the internal of Laccase-Carbon nanotubes was clearly higher than that of carbon nanotubes. Additionally, Scanning Electron Microscope, BET-specific surface area and Fourier Transform Infrared Spectroscopy were utilized to observe the microstructure of enzyme immobilization. This biomimetic nanocomposite sheds light upon conventional wastewater treatment processes for recalcitrant micro-pollutants. Image 1 • Laccase-CNTs nanocomposites were prepared by laccase immobilization onto CNTs. • The Laccase-CNTs exhibited a very high enzyme loading and laccase activity. • Laccase-CNTs had a much better pollutant removal and more stable performance than CNTs. • The adsorption mechanism models of Laccase-CNTs (thermodynamics, kinetics and particle diffusion) were calculated. • Adsorption capacity can be regenerated timely by enzymatic degradation. [ABSTRACT FROM AUTHOR]

Abstract There is a large amount of studies surrounding the usage of agro-industrial waste (AIW) for the adsorptions of organic pollutants (dyes) and inorganic pollutants (heavy metals) in water/wastewater. This method is normally treated as an alternative approach to the conventional water/wastewater treatment. However, there are some increasing interests for investigators to identify novel adsorption materials for pollutants removal. It is particularly noteworthy that most AIW wastes are not currently used at the original state, but modified in a variety of ways to reinforce the porosity and adsorption surface area of the material. Nanostructuring, activation, carbonization, and grafting are some common modification technologies of agricultural waste adsorbents. Besides, the characteristic, preparation and application of adsorbents from various industrial wastes, including natural materials and biosorbents, were summarized. Additionally, the challenges and perspectives for future researches of waste-derived adsorbents were studied. This review provides an important insight on using AIWs as precursor materials for preparing adsorbents in water/wastewater treatment. Highlights • Waste materials from agro-industry were used as adsorbents to remove pollutants. • Various modification methods for AIW were introduced. • The characteristic, preparation and application of AIW were summarized. • The challenges and perspectives of AIW for future researches were studied. [ABSTRACT FROM AUTHOR]

Mesoporous carbon derived from biomass exhibits high drug adsorption capacity and the degradability under both enzymatic and mild chemical conditions. [Display omitted] • Biomass-derived carbon represents excellent drug adsorption capacity. • The carbon could be degraded under very mild conditions. • The degradation occurs via a HO oxidation process. Degradability is a key safety issue when choosing materials for biomedical applications and environmental protection. This factor greatly limits the application of porous carbon in these areas due to the inert and stable nature of carbon network. In this work, this conflict could be well-resolved by rational designing a mesoporous carbon (MC) with biomass as a carbon source. The retained oxygen-containing species simultaneously increase drug adsorption capacity and the degradability of MC. The maximum adsorption quantity for doxorubicin over MC can reach 395.3 mg/g, about 3-fold over carbon nanotubes. The detailed analysis reveals that the degradation of MC occurs via a radical mediated oxidation process. The high electron density feature of MC facilitates the electrophilic addition reaction in the presence of HO. During this process, the carbon network is gradually degraded into fragments, carbon nanodots and ultimately to CO 2. This work opens up a new way to fabricate degradable porous materials and provides a promising material for the practical application in biomedical and environmental field. [ABSTRACT FROM AUTHOR]

The construction of three-dimensional ultramicroporous porous organic framework named TAM-POF possessing high surface areas, high-density N sites and suitable pore size achieves a high SO 2 dynamic adsorption capacity of 2.92 mmol g−1 in ternary gas mixture and a record-high SO 2 /CO 2 (1 2 4) and 3-methylthiophene/n-octane (42) breakthrough selectivities. [Display omitted] • A three-dimensional ultramicroporous POF (TAM-POF) was synthesized. • TAM-POF can capture SO 2 in flue gases and aromatic sulfides in liquid fuels. • A record-high SO 2 dynamic adsorption capacity of 2.92 mmol g−1 was achieved. • TAM-POF exhibits superior SO 2 /CO 2 and 3-methylthiophene/n-octane selectivity. The governance of sulfur dioxide emissions in the atmosphere is a global challenge. Herein, a three-dimensional ultramicroporous porous organic framework named TAM-POF with high surface areas, abundant accessible N sites and suitable pore size was synthesized for elimination of SO 2 in flue gases and aromatic sulfides in liquid fuels. The adsorption and separation performance of TAM-POF is investigated by equilibrium gas adsorption, instant adsorption rates and column breakthrough experiments. A record-high SO 2 dynamic adsorption capacity of 2.92 mmol g−1 in ternary gas mixture (0.5/10/89.5, v/v/v, SO 2 /CO 2 /N 2) and SO 2 /CO 2 (1 2 4) and 3-methylthiophene/n-octane (42) selectivities were achieved in TAM-POF. The strong interaction between adsorbents and TAM-POF, as well as appropriate pore apertures are the main reason for their excellent desulfurization performance, which are also evidenced by theory simulation. [ABSTRACT FROM AUTHOR]

• SO 2 capture from flue gas in MOF-808 and multi-amine carboxylic acid (EDTA) decorated MOF-808 is examined. • Ultra-high SO 2 capture efficiency and highly reversible SO 2 capture ability are achieved in EDTA-MOF-808 under real condition. • The SO 2 adsorption configuration in EDTA-MOF-808 is explained in detail by DFT theoretical calculations. The efficient capture of SO 2 after the combustion of fossil fuels is of great challenge as the low SO 2 concentration (<500 ppm) and coexisting with CO 2 , water, O 2 in flue gas. Robust zirconium-based MOFs possessing accessible polar sites usually have high SO 2 adsorption capacity but poor durably in adsorption desulfurization due to the acidic sulfate deposition on the Zr-O cluster. Herein, a Zr-O cluster post-modification method was introduced in a Zr-MOF (MOF-808) to form EDTA-MOF-808 (EDTA, ethylene diaminetetraacetic acid) for selective and durable removal of SO 2. The introduction of EDTA not only improve their SO 2 adsorption capacity, but also sharply increase their SO 2 /CO 2 selectivity (57.2 vs 8.9) and SO 2 /N 2 selectivity (1915.8 vs 292.7) at low SO 2 partial pressure. Moreover, the synergistic effects of dipole and hydrogen bonding interaction between SO 2 and EDTA in EDTA-MOF-808 make the capture of SO 2 in a reversible manner, which can prevent the formation of S(VI) species in Zr-MOF. DFT calculation confirmed that SO 2 was interacted with EDTA through moderate dipole–dipole interaction (S(SO 2) with N(EDTA)) and hydrogen bonds (H(–COOH) with O(SO 2)). Systematic investigations including thermodynamic SO 2 adsorption, dynamic breakthrough experiments, stability tests and DFT-calculations in both MOF-808 and EDTA-MOF-808 confirmed the efficient performance of post modification of Zr-O clusters with EDTA in Zr-MOFs for durable SO 2 capture. [ABSTRACT FROM AUTHOR]

• A novel Fe-Mn binary oxide-biochar composite (FMBC) was prepared. • FMBC was effective for Cd(II) removal (95.23 mg/g) from water. • Dominant adsorption mechanism was Cd(II) precipitation with ferromanganese oxides. In this study, a pristine biochar (BC) and Fe-Mn binary oxide-biochar (FMBC) were prepared using Pennisetum sp. straw as the feedstock for Cd(II) removal from aqueous solutions. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and specific surface area (SSA) analyses revealed the physico-chemical characteristics of the pristine and designer adsorbents, suggesting that an ultrasonic treatment during synthesis enhanced the SSA and pore volume of the BC, and assisted successful loading of Fe-Mn binary oxide particles on the BC surface. The Cd(II) adsorption data of the adsorbents were fitted to the Langmuir isothermal and pseudo-second-order kinetic models. At a system temperature of 25 °C and pH 5, the maximum Cd(II) adsorption capacities of BC (30.58 mg/g) and FMBC (95.23 mg/g) were obtained. Multiple Cd(II) adsorption mechanisms by FMBC were identified, including precipitation with minerals, complexation with surface functional groups, Cd(II)-π interactions, and cation exchange. As the most dominant adsorption mechanism, Cd-O bonds were formed on the FMBC surfaces precipitating Cd(OH) 2 (63.9 wt%) and CdO (36.1 wt%). The FMBC thus could be potentially used as an effective adsorbent for Cd(II) removal from aqueous solutions. [ABSTRACT FROM AUTHOR]