Development of natural attapulgite derived ferromanganese spinel oxides as heterogeneous catalysts for persulfate activation of tetracycline degradation.

Ferromanganese spinel oxides (MnFe2O4, MFO) have been proven effective in activating persulfate for pollutants removal. However, their inherent high surface energy often leads to agglomeration, diminishing active sites and consequently restricting catalytic performance. In this study, using Al-MCM-41 (MCM) mesoporous molecular sieves derived from natural attapulgite as a support, the MFO/MCM composite was synthesized through dispersing MnFe2O4 nanoparticles on MCM carrier by a simple hydrothermal method, which can effectively activate persulfate (PS) to degrade Tetracycline (TC). The addition of Al-MCM-41 can effectively improve the specific surface area and adsorption performance of MnFe2O4, but also reduce the leaching amount of metal ions. The MFO/MCM composite exhibited superior catalytic reactivity towards PS and 84.3% removal efficiency and 64.7% mineralization efficiency of TC (20 mg/L) was achieved in 90 min under optimized conditions of 0.05 mg/L catalyst dosage, 5 mM PS concentration, room temperature and no adjustment of initial pH. The effects of various stoichiometric MFO/MCM ratio, catalyst dosage, PS concentration, initial pH value and co-existing ions on the catalytic performance were investigated in detail. Moreover, the possible reaction mechanism in MFO-MCM/PS system was proposed based on the results of quenching tests, electron paramagnetic resonance (EPR) and XPS analyses. Finally, major degradation intermediates of TC were detected by liquid chromatography mass spectrometry technologies (LC-MS) and four possible degradation pathways were proposed. This study enhances the design approach for developing highly efficient, environmentally friendly and low-cost catalysts for the advanced treatment process of antibiotic wastewater.

Electrochemical Performance of Nitrogen Self-Doping Carbon Materials Prepared by Pyrolysis and Activation of Defatted Microalgae.

Pyrolysis and activation processes are important pathways to utilize residues after lipid extraction from microalgae in a high-value way. The obtained microalgae-based nitrogen-doped activated carbon has excellent electrochemical performance. It has the advantage of nitrogen self-doping using high elemental nitrogen in microalgae. In this study, two kinds of microalgae, Nanochloropsis and Chlorella, were used as feedstock for lipid extraction. The microalgae residue was firstly pyrolyzed at 500 °C to obtain biochar. Then, nitrogen-doped activated carbons were synthesized at an activation temperature of 700-900 °C with different ratios of biochar and KOH (1:1, 1:2, and 1:4). The obtained carbon materials presented rich nitrogen functional groups, including quaternary-N, pyridine-N-oxide, pyrrolic-N, and pyridinic-N. The nitrogen content of microalgae-based activated carbon material was up to 2.62%. The obtained materials had a specific surface area of up to 3186 m2/g and a pore volume in the range of 0.78-1.54 cm3/g. The microporous pore sizes of these materials were distributed at around 0.4 nm. Through electrochemical testing such as cyclic voltammetry and galvanostatic charge-discharge of materials, the materials exhibited good reversibility and high charge-discharge efficiency. The sample, sourced from microalgae Chlorella residue at activation conditions of 700 °C and biochar/KOH = 1:4, exhibited excellent endurance of 94.1% over 5000 cycles at 2 A/g. Its high specific capacitance was 432 F/g at 1 A/g.

Recent developments and perspectives of MXene-Based heterostructures in photocatalysis.

Energy crises and environmental degradation are serious in recent years. Inexhaustible solar energy can be used for photocatalytic hydrogen production or CO2 reduction to reduce CO2 emissions. At present, the development of efficient photocatalysts is imminent. MXene as new two-dimensional (2D) layered material, has been used in various fields in recent years. Based on its high conductivity, adjustable band gap structure and sizable specific surface area, the MXene is beneficial to hasten the separation and reduce the combination of photoelectron-hole pairs in photocatalysis. Nevertheless, the re-stacking of layers because of the strong van der Waals force and hydrogen bonding interactions seriously hinder the development of MXene material as photocatalysts. By contrast, the MXene-based heterostructures composed of MXene nanosheets and other materials not only effectively suppress the re-stacking of layers, but also show the superior synergistic effects in photocatalysis. Herein, the recent progress of the MXene-based heterostructures as photocatalysts in energy and environment fields is summarized in this review. Particularly, new synthetic strategies, morphologies, structures, and mechanisms of MXene-based heterostructures are highlighted in hydrogen production, CO2 reduction, and pollutant degradation. In addition, the structure-activity relationship between the synthesis strategy, components, morphology and structure of MXene-based heterostructures, and their photocatalytic properties are elaborated in detail. Finally, a summary and the perspectives on improving the application study of the heterostructures in photocatalysis are presented.

Manipulating Li2 S Redox Kinetics and Lithium Dendrites by Core-Shell Catalysts under High Sulfur Loading and Lean-Electrolyte Conditions.

For practical lithium-sulfur batteries (LSBs), the high sulfur loading and lean-electrolyte are necessary conditions to achieve the high energy density. However, such extreme conditions will cause serious battery performance fading, due to the uncontrolled deposition of Li2 S and lithium dendrite growth. Herein, the tiny Co nanoparticles embedded N-doped carbon@Co9 S8 core-shell material (CoNC@Co9 S8 NC) is designed to address these challenges. The Co9 S8 NC-shell effectively captures lithium polysulfides (LiPSs) and electrolyte, and suppresses the lithium dendrite growth. The CoNC-core not only improves electronic conductivity, but also promotes Li+ diffusion as well as accelerates Li2 S deposition/decomposition. Consequently, the cell with CoNC@Co9 S8 NC modified separator delivers a high specific capacity of 700 mAh g-1 with a low-capacity decay rate of 0.035% per cycle at 1.0 C after 750 cycles under a sulfur loading of 3.2 mg cm-2 and a E/S ratio of 12 µL mg-1 , and a high initial areal capacity of 9.6 mAh cm-2 under a high sulfur loading of 8.8 mg cm-2 and a low E/S ratio of 4.5 µL mg-1 . Besides, the CoNC@Co9 S8 NC exhibits an ultralow overpotential fluctuation of 11 mV at a current density of 0.5 mA cm-2 after 1000 h during a continuous Li plating/striping process.

Dual-Conductive CoSe2 @TiSe2 -C Heterostructures Promoting Overall Sulfur Redox Kinetics under High Sulfur Loading and Lean Electrolyte.

Although lithium-sulfur batteries (LSBs) possess a high theoretical specific capacity and energy density, the inherent problems including sluggish sulfur conversion kinetics and the shuttling of soluble lithium polysulfides (LiPSs) have severely hindered the development of LSBs. Herein, cobalt selenide (CoSe2 ) polyhedrons anchored on few-layer TiSe2 -C nanosheets derived from Ti3 C2 Tx MXenes (CoSe2 @TiSe2 -C) are reported for the first time. The dual-conductive CoSe2 @TiSe2 -C heterostructures can accelerate the conversion reaction from liquid LiPSs to solid Li2 S and promote Li2 S dissociation process through high conductivity and lowered reaction energy barriers for promoting overall sulfur redox kinetics, especially under high sulfur loadings and lean electrolyte. Electrochemical analysis and density functional theory calculation results clearly reveal the catalytic mechanisms of the CoSe2 @TiSe2 -C heterostructures from the electronic structure and atomic level. As a result, the cell with CoSe2 @TiSe2 -C interlayer maintains a superior cycling performance with 842.4 mAh g-1  and a low-capacity decay of 0.031% per cycle over 800 cycles at 1.0 C under a sulfur loading of 2.5 mg cm-2 . More encouragingly, it with a high sulfur loading of ≈7.0 mg cm-2  still harvests a high areal capacity of ≈6.25 mAh cm-2  under lean electrolyte (electrolyte/sulfur, E/S ≈ 4.5 µL mg-1 ) after 50 cycles at 0.05 C.

Facial Nerve Schwannoma Extending to Jugular Foramen: A Case Report.

Facial nerve schwannoma (FNS) is a benign, slow-growing schwannoma that originates from Schwann cells. Facial nerve schwannoma is the most common tumor of the facial nerve but rare and only accounts for 0.15% to 0.8% of intracranial neurinomas. It may be manifested as asymmetric hearing loss, facial palsy, and hemifacial spasm. A 56-year-old woman was transferred to our department, because of pain behind the right ear and spasm of the right lateral muscle for more than 2 years and pulsatile tinnitus for half a year. Based on the preoperative medical history, physical signs, and auxiliary examination, it was diagnosed with jugular foramen (JF) space-occupying lesion. We removed the tumor through the infratemporal fossa type A approach and found that the tumor originated from the facial nerve. After the tumor resection, sural nerve transplantation was performed. The patient demonstrated postoperative facial palsy (House-Brackman grade VI) and was smoothly discharged after good recovery. Facial nerve schwannoma rarely invades the JF, and the most common tumor in the JF is the glomus jugular tumor, followed by the posterior cranial schwannoma. They have common symptoms, making it difficult to obtain a correct diagnosis. Clinical data, medical history, and auxiliary examinations should be carefully analyzed to avoid misdiagnosis or mistreatment. Infratemporal fossa type A approach is an effective method for treating FNS of JF.

Oxygen vacancies assist a facet effect to modulate the microstructure of TiO2 for efficient photocatalytic O2 activation.

Defect engineering is recognized as an effective route to obtaining highly active photocatalytic materials. However, the current understanding of the role of defects in photocatalysts mainly comes from their independent functional analysis, ignoring the synergy between defects and the chemical environment, especially with crystal facets. Herein, oxygen vacancy (VO)-rich TiO2 nanostructures with different dominant exposed facets were prepared, and the microstructural changes induced by the synergy between the VO and facet effect and the performance difference of photocatalytic O2 activation were explored. The results showed that the combination of high concentration VO and the {101} facet is more conducive to improving the photocatalytic performance of TiO2, which is significantly superior to the combination of low concentration VO and the {101} facet as well as the combination of high concentration VO and the {001} facet. The experimental and theoretical results clarified the dependence of each stage of photocatalysis on two factors. Specifically, VO plays a more significant role in energy band regulation, improving the dynamic behavior of photogenerated charges and enhancing the adsorption and activation of O2, while the facet effect made more contributions to reducing the thermodynamic energy barrier of ROS formation and conversion. The excellent ability of O2 activation enables T101-VO to show potential application characteristics in the removal of RhB and bacterial disinfection. This work established a link between defect and facet effects, providing new insights into understanding defect function in photocatalysts.

Correction to "Surfactant-Assisted Growth of a Conversion-Type Binary Metal Oxide-Based Composite Electrode for Boosting the Reversible Lithium Storage".

[This corrects the article DOI: 10.1021/acsomega.0c01315.].

Surfactant-Assisted Growth of a Conversion-Type Binary Metal Oxide-Based Composite Electrode for Boosting the Reversible Lithium Storage.

High-performance anode materials play a crucial role in paving the development of next-generation lithium-ion batteries (LIBs). NiCo2O4, as a typical binary metal oxide, has been extensively demonstrated to possess higher capacity and electrochemical activity compared with a monometal oxide such as NiO or Co3O4. However, the advances in the application of LIBs are usually limited by the relatively low electrical conductivity and large volume change during repeated charging/discharging processes. Herein, a NiCo2O4@carbon nanotube (CNT) composite electrode with advanced architecture is developed through a facile surfactant-assisted synthetic strategy. The introduced polyvinyl pyrrolidone can greatly facilitate the heterogeneous nucleation and growth of the NiCo precursor on CNTs and thus benefit the uniform transformation to a well-confined NiCo2O4@CNT composite. The CNTs combined with NiCo2O4 tightly act as both a conductive network for enhancing the ion/electron transfer and a support for mitigating the volume expansion of NiCo2O4. As a result, the NiCo2O4@CNT electrode exhibits a high initial capacity of 830.3 mA h g-1 and a good cycling stability of 608.1 mA h g-1 after 300 cycles at 2000 mA g-1.

Antifungal effects of BiOBr nanosheets carrying surfactant cetyltrimethylammonium bromide.

BiOBr nanosheets are important photocatalytic nanomaterials. However, their biological effects remain to be explored. In this study, we investigated the antifungal effect of BiOBr nanosheets on Candida albicans. Strikingly, the nanosheets strongly inhibited the growth of C. albicans [IC50=(96±4.7) mg/L], hyphal development and biofilm formation. Compareed to the antifungal effect of the cationic surfactant cetyltrimethylammonium bromide, the inhibitory effect of the nanosheets on fungal pathogen was attributed to cetyltrimethylammonium bromide adsorbed by the nanosheets. Thermal gravity analysis and cetyltrimethylammonium bromide release experiment indicated that only 0.42% cetyltrimethylammonium bromide on BiOBr nanosheets was released. Taken together, this study uncovers the contribution of surfactant released from the nanosheets to their antifungal activity.

Hierarchical N-Rich Carbon Sponge with Excellent Cycling Performance for Lithium-Sulfur Battery at High Rates.

Lithium-sulfur batteries (LSBs) are receiving extensive attention because of their high theoretical energy density. However, practical applications of LSBs are still hindered by their rapid capacity decay and short cycle life, especially at high rates. Herein, a highly N-doped (≈13.42 at %) hierarchical carbon sponge (HNCS) with strong chemical adsorption for lithium polysulfide is fabricated through a simple sol-gel route followed by carbonization. Upon using the HNCS as the sulfur host material in the cathode and an HNCS-coated separator, the battery delivers an excellent cycling stability with high specific capacities of 424 and 326 mA h g-1 and low capacity fading rates of 0.033 % and 0.030 % per cycle after 1000 cycles under high rates of 5 and 10 C, respectively, which are superior to those of other reported carbonaceous materials. These impressive cycling performances indicate that such a battery could promote the practical application prospects of LSBs.

Efficient NiSe-Ni3Se2/Graphene Electrocatalyst in Dye-Sensitized Solar Cells: The Role of Hollow Hybrid Nanostructure.

Hollow and hybrid nanomaterials are excellent electrocatalysts on account of their novel electrocatalytic properties compared with homogeneous solid nanostructures. In this report, NiSe-Ni3Se2 hybrid nanostructure with morphology of hollow hexagonal nanodisk was synthesized in situ on graphene. A series of NiSe-Ni3Se2/RGO with different phase constitutions and nanostructures were obtained by controlling the durations of solvothermal treatment. Because of their unique hollow and hybrid structure, NiSe-Ni3Se2/RGO hollow nanodisks exhibited higher electrocatalytic performance than NiSe/RGO and solid NiSe-Ni3Se2/RGO nanostructure for reducing I3(-) as counter cell (CE) of dye-sensitized solar cells (DSSCs). Additionally, NiSe-Ni3Se2/RGO hollow nanodisks achieved much lower charge transfer resistance (Rct = 0.68 Ω) and higher power conversion efficiency (PCE) (7.87%) than those of Pt (Rct = 1.41 Ω, PCE = 7.28%).

Facile Preparation and Lithium Storage Properties of TiO2 @Graphene Composite Electrodes with Low Carbon Content.

Over the past decade, TiO2 /graphene composites as electrodes for lithium ion batteries have attracted a great deal of attention for reasons of safety and environmental friendliness. However, most of the TiO2 /graphene electrodes have large graphene content (9-40 %), which is bound to increase the cost of the battery. Logically, reducing the amount of graphene is a necessary part to achieve a green battery. The synthesis of TiO2 nanosheets under solvothermal conditions without additives is now demonstrated. Through mechanical mixing TiO2 nanosheets with different amount of reduced graphene (rGO), a series of TiO2 @graphene composites was prepared with low graphene content (rGO content 1, 2, 3, and 5 wt %). When these composites were evaluated as anodes for lithium ion batteries, it was found that TiO2 +3 wt % rGO manifested excellent cycling stability and a high specific capacity (243.7 mAh g(-1) at 1 C; 1 C=167.5 mA g(-1) ), and demonstrated superior high-rate discharge/charge capability at 20 C.

Reduced graphene oxide-supported TiO2 fiber bundles with mesostructures as anode materials for lithium-ion batteries.

Although the synthesis of mesoporous materials is well established, the preparation of TiO2 fiber bundles with mesostructures, highly crystalline walls, and good thermal stability on the RGO nanosheets remains a challenge. Herein, a low-cost and environmentally friendly hydrothermal route for the synthesis of RGO nanosheet-supported anatase TiO2 fiber bundles with dense mesostructures is used. These mesostructured TiO2 -RGO materials are used for investigation of Li-ion insertion properties, which show a reversible capacity of 235 mA h g(-1) at 200 mA g(-1) and 150 mA h g(-1) at 1000 mA g(-1) after 1000 cycles. The higher specific surface area of the new mesostructures and high conductive substrate (RGO nanosheets) result in excellent lithium storage performance, high-rate performance, and strong cycling stability of the TiO2 -RGO composites.

Synthesis of mesoporous wall-structured TiO2 on reduced graphene oxide nanosheets with high rate performance for lithium-ion batteries.

Mesoporous wall-structured TiO2 on reduced graphene oxide (RGO) nanosheets were successfully fabricated through a simple hydrothermal process without any surfactants and annealed at 400 °C for 2 h under argon. The obtained mesoporous structured TiO2 -RGO composites had a high surface area (99 0307 m(2) g(-1)) and exhibited excellent electrochemical cycling (a reversible capacity of 260 mAh g(-1) at 1.2 C and 180 mAh g(-1) at 5 C after 400 cycles), demonstrating it to be a promising method for the development of high-performance Li-ion batteries.

TiO2-B nanorods on reduced graphene oxide as anode materials for Li ion batteries.

Composites of TiO2-B nanorods and reduced graphene oxide (RGO) were prepared through a simple two-step hydrothermal process followed by subsequent heat treatment in argon. The obtained TiO2-B nanorods had a small size (∼10 nm diameter of the nanorod) and a uniform morphology. Importantly, the synergistic effect of RGO nanosheets and nanostructured TiO2-B leads to electrodes composed of the TiO2-B-RGO nanocomposites which exhibit excellent cycling stability and rate capability (260 mA h g(-1) at 1 C and 200 mA h g(-1) at 2 C after 300 cycles and 140 mA h g(-1) at 20 C).

Rutile TiO2 nanobundles on reduced graphene oxides as anode materials for Li ion batteries.

A simple and steerable method was adopted to synthesize well-distributed rutile TiO2 nanobundles on reduced graphene oxides through two-step hydrothermal methods. The rutile TiO2-RGO composites were used as the anode materials in lithium ion batteries for investigation, which had an original morphology and a reversible capacity of 300 mA h g(-1) at 0.6 C and 200 mA h g(-1) at 1.2 C after 500 cycles.