Explore the vast range of titles available.

In the new era of modern flexible and bendable technology, graphene-based materials have attracted great attention. The excellent electrical, mechanical, and optical properties of graphene as well as the ease of functionalization of its derivates have enabled graphene to become an attractive candidate for the construction of flexible devices. This paper provides a comprehensive review about the most recent progress in the synthesis and applications of graphene-based composites. Composite materials based on graphene, graphene oxide (GO), and reduced graphene oxide (rGO), as well as conducting polymers, metal matrices, carbon–carbon matrices, and natural fibers have potential application in energy-harvesting systems, clean-energy storage devices, and wearable and portable electronics owing to their superior mechanical strength, conductivity, and extraordinary thermal stability. Additionally, the difficulties and challenges in the current development of graphene are summarized and indicated. This review provides a comprehensive and useful database for further innovation of graphene-based composite materials.

Double transition metal (DTM) MXenes are a recently discovered class of two‐dimensional composite nanomaterials with excellent potential in energy storage applications. Since their emergence in 2015, DTM MXenes have expanded their composition boundary beyond traditional single‐metal carbide and nitride MXenes. DTM MXenes offer tunable structures and properties through variations in the constituent transition metals and positioning within the layered lattice. These MXenes can exist in two primary forms: ordered DTMs and solid solutions. The compositional versatility of DTM MXenes offers opportunities to enhance their performance in electrochemical energy storage applications. However, the quality, stability, and surface chemistry of DTM MXenes are influenced by several factors, including the etching process, etchant type, and synthesis route. Currently, limited literature is available on experimentally synthesized DTM MXenes, with most studies focusing on carbide‐based MXenes. Most of the articles have dedicated their efforts only to generalized synthesis strategies. Although extensive theoretical studies have explored the suitability of etchants, synthesis parameters, and methods for producing high‐quality MXene with selective terminal functional groups, their stability issues have not been thoroughly examined. This review addresses various types of DTM MXenes, their synthesis techniques, and the impact of these methods on their physicochemical properties and electrochemical performance. Additionally, it provides a critical analysis of the causes of instability in MXenes, particularly DTMs, from synthesis to application. The challenges associated with these materials are discussed, along with opportunities and prospects for enhancing synthesis, structural tuning, surface modification, and applications in electrochemical energy storage. This review presents the synthesis, physicochemical properties, and electrochemical performance of double transition metal (DTM) MXenes, emphasizing the challenges and instabilities in their production and application. The work highlights the potential of DTM MXenes in energy storage and offers insights for improving their stability and functionality.

In recent era of modern and bendable technology, energy dearth arises as a paramount subject around the globe with a dire demand of flexible and lightweight energy storage devices. This study targets fabrication of reduced graphene oxide (rGO) and utility of abundantly available, cost effective, and environment friendly lignocelluloses (LC) fibers extracted from Carica papaya source, as a binder to bind active material (rGO) as robust and compact paper sheet. Fabricated samples were analyzed by X-ray diffraction for crystallographic analysis, Scanning electron microscopy, Transmission electron microscope for morphology, Fourier transform infrared spectroscopy for structural bonding, and Raman spectroscopy for vibrational modes. Robust and bendable rGO/LC paper electrode was tested for energy storage application by employing in different characterizations, i.e., cyclic voltammetry for capacitive behavior, galvanostatic charge–discharge for symmetric EDLC, and electrochemical impedance spectroscopy for resistive charge kinetics, respectively. rGO/LC composite sheet employed as working electrode in 3-electrode CV measurements and revealed specific capacitance of 591 F/g at a scan rate of 5 mV/s by keeping the undistorted shape of voltammograms at higher scan rates which present it as a suitable candidate for modern flexible and energy storage devices. rGO/LC-based symmetric cell revealed the highest specific capacitance of 228 F/g at applied current density of 0.1 A/g, the energy density of 6.3 Wh/kg, and power density of 129 W/kg, respectively. rGO/LC-based symmetric cell confirmed the cycling stability by revealing capacitance retention of 82% after 200 cycles. It can conclude that biomass-based rGO paper sheet can be a potential candidate as environmentally safe with remarkable electrochemical activity in energy storage applications.

ABSTRACT MXenes, a family of emerging two‐dimensional materials offer enriched surface chemistry, high electrical conductivities, large specific surface area, intrinsic physicochemical properties, and excellent mechanical stability. However, restacking of MXene sheets limit their electrochemical performance. To overcome this limitation, recent advancements have focused on developing MXene composites with metal phosphates/phosphides (MXene/MPs). This review discusses the applications of MXene/MPs composites in energy storage and conversion applications. The incorporation of MPs into MXenes not only addresses the restacking issue and aggregation problems, but also enhances the overall electrochemical performance of energy storage and conversion systems. The review concludes with a summary of the current research status and future prospects for MXene/MPs‐based composites in energy applications. This review focuses on MXene and their composites with metal phosphides and phosphates (MXene/MPs) for electrochemical energy storage and conversion applications. A thorough approach has been adopted to discuss the synthesis, properties, applications, and future aspects of MXene–TMPs.

The development of transition metal (TM) catalysts to replace precious metals has garnered increasing interest. Specifically, platinum (Pt)-based catalysts have been extensively investigated for their electrochemical performance in hydrogen evolution reaction (HER), which offer a clean means of producing hydrogen fuel without carbon emissions. However, the reliance on Pt-based catalysts has hindered the progress of HER development. Therefore, researchers have explored metal-organic frameworks (MOFs) as a substitute for noble Pt-based catalysts to address this issue. Nevertheless, the low electroconductivity of pure MOFs restricts their application in electrochemical fields. To overcome this limitation, MXenes have emerged as a promising two-dimensional (2D) material for coupling with MOFs to create an electrocatalyst with high electrical conductivity, a large surface area, and a tunable structure. In this study, we report the synthesis of a Ti3C2Tx (MXene) nanosheet-encapsulated MOFs catalyst (Ti3C2Tx@ZIF-8) with high activity and a low cost by encapsulating the precursor with ZIF-8 for HER in alkaline media. The catalyst exhibits an overpotential of only 507 mV at 20 mA/cm2 and a low Tafel slope value of 77 mV/dec. Additionally, cyclic voltammetry (CV) indicates an electrochemical active surface area (ECSA) of 122.5 cm2, and chronopotentiometry demonstrates the stable nature of the catalyst over 20 h without any significant changes in the overpotential value. The excellent electrochemical properties of Ti3C2Tx@ZIF-8 suggest its potential as a promising material for energy conversion applications.

In this work, bismuth-doped titania (Bi x TiO 2 ) with improved oxygen vacancies was synthesized by sol-gel protocol as a novel peroxymonosulfate (PMS, HSO 5 − ) activator. HSO 5 − and adsorbed oxygen molecules could efficiently be transformed into their respective radicals through defect ionization to attain charge balance after their trapping on oxygen vacancies of the catalyst. XRD study of Bi x TiO 2 with 5 wt% Bi (5BiT) revealed anatase, crystalline nature, and successful doping of Bi into TiO 2 crystal lattice. The particle size obtained from BET data and SEM observations was in good agreement. PL spectra showed the formation rates of • OH by 3BiT, 7BiT, 5BiTC, and 5BiT as 0.720, 1.200, 1.489, and 2.153 μmol/h, respectively. 5BiT catalyst with high surface area (216.87 m 2 g −1 ) and high porosity (29.81%) was observed the excellent HSO 5 − activator. The catalytic performance of 0BiT, 3BiT, 5BiT, and 7BiT when coupled with 2 mM HSO 5 − for recalcitrant flumequine (FLU) removal under dark was 10, 27, 55, and 37%, respectively. Only 5.4% decrease in catalytic efficiency was observed at the end of seventh cyclic run. Radical scavenging studies indicate that SO 4 •− is the dominant species that caused 62.0% degradation. Moreover, strong interaction between Bi and TiO 2 through Bi-O-Ti bonds prevents Bi leaching (0.081 mg L −1 ) as shown by AAS. The kinetics, degradation pathways, ecotoxicity, and catalytic mechanism for recalcitrant FLU were also elucidated. Cost-efficient, environment-friendly, and high mineralization recommends this design strategy; Bi x TiO 2 /HSO 5 − system is a promising advanced oxidation process for the aquatic environment remediation.

The greatest obstacle for scientists is to develop an effective HIV vaccine. An effective vaccine represents the last hope for halting the unstoppable global spread of HIV and its catastrophic clinical consequences. Creating this vaccine has been challenging due to the virus’s extensive genetic variability and the unique role of cytotoxic T lymphocytes (CTL) in containing it. Innovative methods to stimulate CTL have demonstrated significant therapeutic advantages in nonhuman primate model systems, unlike traditional vaccination techniques that are not expected to provide safe and efficient protection against HIV. Human clinical trials are currently evaluating these vaccination strategies, which involve plasmid DNA and live recombinant vectors. This review article covers the existing vaccines and ongoing trial vaccines. It also explores the different approaches used in developing HIV vaccines, including their molecular mechanisms, target site effectiveness, and potential side effects.

A field study was conducted on the reuse of wastewater from Mardan city to evaluate its risk of contaminating soil and wheat grains at different NPK levels. Three irrigation sources i.e. waste water (WW), canal water (CW) and alternate waste + canal water (WW+CW) were applied to wheat (cv Atta Habib 2010) grown at 0, 50, 75 and 100% NPK levels of 120:90:60 kg N:P 2 O 5 :K 2 O ha -1 at Palatoo Research Farm, Amir Muhammad Khan Campus, Mardan during 2015.The results showed higher grain and biomass yields in WW irrigated plots as compared to CW at NPK levels up to 50% of recommending dose revealing supplementing nutrient requirements in deficient conditions. However, irrigation of WW at higher NPK levels especially at or beyond 75% of recommended dose tended to reduce the crop yield that could be associated with heavy metals toxicity and nutritional imbalances. The use of WW substantially increased AB-DTPA extractable Zn, Mn, Pb, Ni and Cd indicating a potential threat to soil contamination. Similarly, WW irrigated wheat had higher concentrations of these heavy metals as compared to CW which limits its use for production purposes without any remediation measures. The alternate use of CW and WW as revealed by its comparative lower contamination in soil and wheat than sole WW could be one of the possible solutions and may increase the time required for threshold soil contamination.

The cultivation of summer vegetables in open-air nutrient film technique (NFT) hydroponics is limited due to the elevated nutrient solution temperature (NST). In this regard, non-electric evaporative-cooling techniques were explored to maintain NST in open-air NFT hydroponics. Four cooling setups were employed by wrapping polyvinyl chloride (PVC) grow pipes with one and two layers of either wet or dry jute fabrics and attaching them with coiled aluminum pipe buried inside a) wet sand-filled brick tunnels (Cooling Setup I), b) two inverted and vertically stacked earthen pots (Cooling Setup II), c) two inverted and vertically stacked earthen pots externally wrapped with wet jute fabric (Wrapped Cooling Setup II), and d) an earthen pitcher wrapped with wet jute fabric (Cooling Setup III). Wrapping grow pipes with two layers of wet jute fabric reduced NST by 5°C as compared to exposed (naked) grow pipes. The double-layer jute fabric-wrapped grow pipes produced 182% more reduction in NST in comparison to single layer-wrapped grow pipes. Additionally, the installation of Wrapped Cooling Setup II and Cooling Setup III outperformed Cooling Setup I and Cooling Setup II through NST reduction of approximately 4°C in comparison to control. Interestingly, Cooling Setup III showed its effectiveness through NST reductions of 193%, 88%, and 23% during 11 a.m.–12 p.m. as compared to Cooling Setup I, Cooling Setup II, and Wrapped Cooling Setup II, respectively. In contrast, Wrapped Cooling Setup II caused NST reductions of 168%, 191%, and 18% during 2–3 p.m. in comparison to Cooling Setup I, Cooling Setup II, and Cooling Setup III, respectively. Thus, the double-layer jute fabric-wrapped grow pipes linked with Wrapped Cooling Setup II can ensure summer vegetable cultivation in open-air NFT hydroponics as indicated by the survival of five out of 12 vegetable plants till harvest by maintaining NST between 26°C and 28°C.

Variations in the estrogen receptor genes, particularly the Xba1 (rs9340799) SNP in the ESR1 gene, may influence the effects of estrogen on male fertility. Results from previous studies on this SNP for male infertility have been inconclusive. This review aimed to determine the association of ESR1 Xba1 (rs9340799) with male infertility. Relevant case–control studies published in English were searched from Google Scholar, Embase, Scopus, Web of Science, Cochrane Library, and PubMed using keywords of ESR, polymorphism, and male infertility. Studies on animals, reviews, and abstracts were excluded. Pooled odds ratios (ORs) were calculated for four genetic models, with heterogeneity assessed by I2. A fixed or random effect model was applied based on I2, and trial sequential analysis (TSA) was conducted with 5% significance for type I error and 95% power. ESR1 expression levels were examined in testes, hypothalamus, prostate, and pituitary using GTEx Analysis. Nine studies (four Asian, four Caucasian, one African) met the criteria. The G allele was protective against infertility overall (OR: 0.80; 95% confidence interval [CI] = [0.70, 0.92]) and in Caucasian men (OR: 0.71; 95% CI = [0.54, 0.92]). Lower infertility risk was observed in Asian (AA vs. GG OR: 0.65; 95% CI = [0.43, 0.98]) and Caucasian men (OR: 0.49; 95% CI = [0.28, 0.83]). TSA indicated no further studies are likely to change these results. No significant change in expression of ESR1 was observed due to this SNP. The present meta-analysis suggests that the SNP Xba1 (rs9340799) in ESR1 is protective against male infertility, with current data sufficient to confirm these findings.