Development of Plasmonic Attapulgite/Co(Ti)Ox Nanocomposite Using Spent Batteries toward Photothermal Reduction of CO2.

The rapid development of the battery industry has brought about a large amount of waste battery pollution. How to realize the high-value utilization of waste batteries is an urgent problem to be solved. Herein, cobalt and titanium compounds (LTCO) were firstly recovered from spent lithium-ion batteries (LIBs) using the carbon thermal reduction approach, and plasmonic attapulgite/Co(Ti)Ox (H-ATP/Co(Ti)Ox) nanocomposites were prepared by the microwave hydrothermal technique. H-ATP had a large specific surface area and enough active sites to capture CO2 molecules. The biochar not only reduced the spinel phase of waste LIBs into metal oxides including Co3O4 and TiO2 but also increased the separation and transmission of the carriers, thereby accelerating the adsorption and reduction of CO2. In addition, H-ATP/Co(Ti)Ox exhibited a localized surface plasmon resonance effect (LSPR) in the visible to near-infrared region and released high-energy hot electrons, enhancing the surface temperature of the catalyst and further improving the catalytic reduction of CO2 with a high CO yield of 14.7 µmol·g-1·h-1. The current work demonstrates the potential for CO2 reduction by taking advantage of natural mineral and spent batteries.

Monolithic Catalysts Supported by Emulsion-Templated Porous Polydivinylbenzene for Continuous Reduction of 4-Nitrophenol.

A monolithic catalyst was fabricated through an emulsion-templating method, postpolymerization modification, and in situ loading of active constituents. To achieve a high specific surface area, divinylbenzene (DVB) was solely employed as the monomer, while the porous structure was adjusted with the porogen content and the types of initiators. Then, anchor points were introduced on the pore wall through nitration and amination of the polymeric scaffold. Using a controlled "silver mirror reaction", monolithic catalysts were obtained after loading of silver nanoparticles (Ag NPs), which was verified from morphological and crystallinity characteristics. The catalytic performance of the resultant monolithic catalyst was determined with the model reduction of 4-nitrophenol (4-NP). In static catalysis, the monolithic catalyst was proved to have a reactively high apparent rate constant and a good reusability. Furthermore, a flow reactor was fabricated with the monolithic catalyst, showing a high efficiency and long-term durability for the continuous reduction of 4-NP. This work broadened the adjustment of porous structures and the subsequent application for emulsion-templated monoliths.

Carbonized Syndiotactic Polystyrene/Carbon Nanotube/MXene Hybrid Aerogels with Egg-Box Structure: A Platform for Electromagnetic Interference Shielding and Solar Thermal Energy Management.

Functional materials for electromagnetic interference (EMI) shielding are a consistently hot topic in the booming communication engineering, proceeding the development that tends to the multifunctional EMI shielding materials. Herein, a series of carbonized syndiotactic polystyrene/carbon nanotube/MXene (CsPS/CNT/MXene) hybrid aerogels were fabricated for EMI shielding and solar thermal energy conversion purposes. To fabricate the hybrid aerogels, a porous CNT/MXene framework was initially prepared using freeze-casting. Subsequently, sPS was infused into the porous structure, followed by hyper-cross-linking and carbonization of sPS under an inert atmosphere. The resulting aerogels exhibited a distinctive egg-box structure, comprising numerous nanofibrous carbon microspheres embedded within the lamellar framework. The mass ratio between CNT and MXene was regulated to identify an optimum aerogel, that is, the CCM-4-6, which exhibited impressive properties including Young's compression modulus of 0.67 MPa, a water contact angle of 137.6 ± 4.1°, a specific surface area of 110 m2 g-1, an electrical conductivity of 43.0 S m-1, and an EMI SE value of 40 dB. Meanwhile, phase-change composites were fabricated through encapsulating paraffin wax within the hybrid aerogels. For the CCM-4-6 aerogel, a noteworthy encapsulation ratio was achieved at about 76.7%, along with remarkable latent heat, good thermal reliability, and commendable solar thermal energy conversion capacity. This study presents a facile route to prepare multifunctional EMI shielding materials.

Janus Hemispheres through Controlled Polymerization-Induced Phase Separations within Wax Droplets.

A series of Janus hemispheres with a patchy hemispherical surface and a flat undersurface were synthesized through controlled polymerization-induced phase separation within emulsified wax droplets. The hemispherical shape was generated through the polymerization of styrene within wax droplets, followed by the grafting of hydrophilic polymers on the exposed surface. Then, the patchy hemispherical surface was achieved after introducing the hydrophobic acrylate monomers within wax droplets and controlling the polymerization-induced phase separation. The morphological evolution of patches was recorded via the reaction time, followed by their morphological regulation through the type, feeding amount, and cross-linking degree of acrylate monomers. A functional monomer, vinyl benzyl chloride (VBC), was also used to copolymerize the patches for grafting a zwitterionic polymer via surface-initiated atom transfer radical polymerization (SI-ATRP). The as-obtained Janus hemispheres were employed to fabricate robust coatings with wettability tuned from superhydrophobicity to underwater superoleophobicity by the grafted zwitterionic polymers.

C,N co-doped TiO2 hollow nanofibers coated stainless steel meshes for oil/water separation and visible light-driven degradation of pollutants.

Complex pollutants are discharging and accumulating in rivers and oceans, requiring a coupled strategy to resolve pollutants efficiently. A novel method is proposed to treat multiple pollutants with C,N co-doped TiO2 hollow nanofibers coated stainless steel meshes which can realize efficient oil/water separation and visible light-drove dyes photodegradation. The poly(divinylbenzene-co-vinylbenzene chloride), P(DVB-co-VBC), nanofibers are generated by precipitate cationic polymerization on the mesh framework, following with quaternization by triethylamine for N doping. Then, TiO2 is coated on the polymeric nanofibers via in-situ sol-gel process of tetrabutyl titanate. The functional mesh coated with C,N co-doped TiO2 hollow nanofibers is obtained after calcination under nitrogen atmosphere. The resultant mesh demonstrates superhydrophilic/underwater superoleophobic property which is promising in oil/water separation. More importantly, the C,N co-doped TiO2 hollow nanofibers endow the mesh with high photodegradation ability to dyes under visible light. This work draws an affordable but high-performance multifunctional mesh for potential applications in wastewater treatment.

Efficient Charge Separation via MoSe2 Nanosheets with Tunable 1T Phase Contents: Piezoreduction of Cr(VI) to Cr(III) and Piezodegradation of RhB.

Piezocatalysis is a promising technology to address environmental pollution by converting mechanical energy into chemical energy. Herein, MoSe2 nanosheets with different 1T phase percentages (ranging from 30 to 80%) were constructed by adjusting hydrothermal temperature. Moreover, the roles of phase engineering in the piezocatalysis were thoroughly investigated by degrading rhodamine B and reducing Cr(VI) in ultrasonic vibration conditions. In particular, MoSe2 prepared at 220 °C (MoSe2-220) exhibits ultrahigh observed constant kobs and degradation rate k, which is superior to most reported catalysts to date. The experimental results indicate that the introduction of the 1T phase increases the active sites of the material, improves the conductivity, and inhibits the recombination of electrons and holes. Moreover, an internal electric field in the 2H phase induced by piezoelectric polarization is facilitated to separate electron-hole pairs, enabling the degradation and reduction to proceed. The capture experiments and EPR tests further confirm that •O2- and •OH are main reactive species, and a rational mechanism is finally put forward. This study offers a clear understanding of phase engineering in piezocatalysis and provides an efficiency strategy to construct highly efficient piezocatalysts.

Boosting photocatalytic reduction of nitrate to ammonia enabled by perovskite/biochar nanocomposites with oxygen defects and O-containing functional groups.

Photocatalytic ammonia synthesis from waste nitrate has emerged as a promising strategy in water treatment; however, the conversion and selectivity still remain a great challenge. Herein, recyclable magnetic perovskite (LaFeO3)/biochar nanocomposites were successfully synthesized by the co-pyrolysis of the lotus biomass and Fe/La salts without extra organic complexants. Results showed that the lotus interacted with the iron ions (Fe3+) and the lanthanum ions (La3+) changing the surface and structural characteristics of catalysts. Oxygen defects of LaFeO3 were enhanced due to biomass introduction, which accelerated the separation of electron-hole pairs. On the other hand, Fe/La salts participated in the modification process of the biochar surface during the carbonization, which promoted the exposure of oxygen-containing functional groups and aromatic structures facilitating the nitrate adsorption. Notably, the redox-active quinone/phenol groups on the biochar surface contributed to the photogenerated electrons exchange favoring the ammonium ion (NH4+) selectivity as direct electron donor. Nitrate conversion reached 98% and ammonia selectivity reached 97% over the LaFeO3/biochar photocatalyst under visible light irradiation, when the mass ratio of lotus and Fe/La salts was optimized. Our findings may potentially provide a green and cost-effective way for ammonia recovery from nitrate contaminants.

Effective adsorption of zeolite/carbon composite molecular sieve synthesized from spent bleaching earth.

Spent bleaching earth (SBE) as an industrious solid rubbish seriously causes the environmental pollution problem. The resourceful utilization of SBE has become increasingly important. In this work, silicon and carbon ingredients derived from SBE were coincidently employed to synthesize a 4A zeolite/carbon composite molecular sieve (4A/CMS). Therein, the graphite carbon components in the form of porous lamellar scattering among the interlayer, surface, and periphery of 4A zeolite promote the rate of mass transfer for the lipophilic gas, which can effectively improve the adsorption property for the volatile organic compounds. The obtained 4A/CMS has large specific surface area, hierarchical pore structure, satisfactory adsorption capacity, and regeneration performance, and its equilibrium adsorption capacity of p-xylene can achieve 209.57 mg·g-1. The pseudo-first-order rate equation is appropriate for the adsorption kinetics. In the end, the formation mechanism of 4A/CMS was illuminated in detail. □ Spent bleaching earth (SBE) as an industrious solid rubbish were utilized resourcefully. Silicon and carbon ingredients from SBE were coincidently employed to synthesize 4A/CMS. Graphitic carbon with hierarchical pore promoted the rate of mass transfer of organic gas. 4A/CMS exhibited excellent adsorption capacity and regeneration performance of p-xylene.

Clay-activated carbon adsorbent obtained by activation of spent bleaching earth and its application for removing Pb(II) ion.

BE/C-A750-1/1 is prepared by carbonizing SBE and then activating with KOH. BE/C-A750-1/1 has good adsorption capacity for Pb(II), and the adsorption capacity for Pb(II) is 206.65 mg/g. The harmful effects of coexisting cations are listed in ascending order: K+ < Na+ < Mg2+. Adsorption and desorption studies show that the adsorption capacity of BE/C-A750-1/1 for Pb(II) after adsorption and desorption 3 times is 183.62 mg/g. The adsorption mechanism mainly includes electrostatic attraction, ion exchange, physical adsorption, and chemical complexation. This suggests that activated BE/C may be a promising candidate for removing Pb(II) from industrial wastewater. Clay/carbon nanocomposites were prepared by carbonizing and activating the spent bleaching earth served as adsorbents for the efficient removal of Pb(II) from wastewater.

Full spectrum driven SCR removal of NO over hierarchical CeVO4/attapulgite nanocomposite with high resistance to SO2 and H2O.

Removal of hazardous NO at low temperature via photo-assisted selective catalytic reduction (photo-SCR) strategy is promising, however fully harvesting of solar energy and achieving high SO2/H2O tolerance still remain a challenge. Herein, the phosphoric acid modified natural attapulgite(P-ATP) was employed as a matrix to immobilize CeVO4 by microwave hydrothermal method. Results show that P-ATP provides abundant active sites facilitating the in situ grow of CeVO4 nanorods on its surface which hierarchically construct a dendritic-like photocatalyst. The near-infrared (NIR) light is upconverted to visible and UV light through CeVO4 which not only broaden the absorption range of solar light, but also build Z-scheme heterostructure with P-ATP enhancing the redox potential of charge carriers. The CeVO4/P-ATP nanocomposite can reach as high as 92 % for NO conversion under full-spectrum solar irradiation, while retaining nearly 60 % conversion under NIR light. Moreover, the catalyst exhibits outstanding tolerance with SO2 and H2O due to the presence of Ce species which can prevent NH3 from being sulfated, while ATP prevent catalyst from being corroded by H2O. This work may open up a new window for full-spectrum driven SCR of NO based on cost-effective mineral catalyst.

Photo-assisted SCR removal of NO by upconversion CeO2/Pr3+/attapulgite nanocatalyst.

The emission of nitrogen oxides has caused severe harm to the ecosystem; thus, the development of low-cost and high-efficiency denitrification catalysts and new methods are of great significance. In this work, a co-precipitation method was employed to prepare Pr-doped CeO2/attapulgite (CeO2/Pr3+/ATP) nanocomposites. X-ray diffraction (XRD), photoluminance spectroscopy (PL), ultraviolet-visible diffuse reflectance (UV-Vis), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HRTEM) were utilized to characterize the products. Results showed that the CeO2/Pr3+ nanoparticles were uniformly coated on the surface of ATP and demonstrated outstanding upconversion effect which converted the visible light to ultraviolet light. The upconversion luminescence of CeO2/Pr3+/ATP was strongest when the molar doping amount of Pr was 1 mol%, and the photo-SCR denitrification achieved the highest of 90% conversion and 95% selectivity when the loading amount of CeO2/Pr3+ was 40 wt%. The ATP and CeO2/Pr3+ constructed an indirect Z-type heterojunction structure mediated by oxygen vacancy which benefited the separation of charge carriers and enhanced the reduction-oxidation potentials, both are responsible for the remarkable denitrification performance.

Z-Scheme Photocatalyst Constructed by Natural Attapulgite and Upconversion Rare Earth Materials for Desulfurization.

The Er3+:CeO2/ATP (attapulgite) nanocomposites were prepared by a facile precipitation method. The samples were characterized by various measurements. XRD and TEM showed that Er3+:CeO2 nanoparticles were well-crystallized and loaded on the surface of ATP. The visible light was converted into ultraviolet light by Er3+:CeO2 as evidenced by upconversion photoluminance (PL) analysis. The mass ratio of Er3+:CeO2 to ATP on the desulfurization efficiency was investigated. Results showed that the desulfurization rate reached 87% under 4 h visible light irradiation when the mass ratio was 4:10. The mechanism was put forward as follows. Er3+:CeO2 and ATP formed Z-scheme heterostructure intermediated by oxygen vacancy, leading to the enhanced separation of photogenerated charges and preservation of high oxidation-reduction potential, both of which favored for the generation of radicals to oxidize sulfur species.