Rational design of dual-ion doped cobalt-free Li-rich cathode materials for enhanced cycle stability of lithium-ion pouch cell batteries.

The synergistic effect of single-crystal structure and dual doping in Li-rich cobalt-free cathode materials was thoroughly investigated. Lithium-ion pouch cells employing Sb/Sn doped Li1.2Mn0.6Ni0.2O2 and graphite exhibited a specific capacity of 191.01 mA h g-1 at 1C rate and exceptionally stable performance upon cycling, with capacity retention of 87.24% of their initial capacity after 250 cycles at 1C rate. The strategic combination of morphology manipulation and dual ion doping has markedly diminished cation mixing and expanded the Li interstitial sites within the cathode lattice. This work offers significant insights into the mechanisms responsible for the structural decline of Li-rich cobalt-free cathodes, emphasizing the importance of stabilizing the cathode lattice structure at high potential. These findings suggest promising potential for this material to meet the demanding energy density criteria for electric vehicles. Finally, this research provides practical strategies for effectively implementing high-voltage cobalt-free cathodes, offering valuable guidance for future applications.

Advancing lithium-sulfur battery efficiency: utilizing a 2D/2D g-C3N4@MXene heterostructure to enhance sulfur evolution reactions and regulate polysulfides under lean electrolyte conditions.

Lithium-sulfur batteries (LSBs) show promise for achieving a high energy density of 500 W h kg-1, despite challenges such as poor cycle life and low energy efficiency due to sluggish redox kinetics of lithium polysulfides (LiPSs) and sulfur's electronic insulating nature. We present a novel 2D Ti3C2 Mxene on a 2D graphitic carbon nitride (g-C3N4) heterostructure designed to enhance LiPS conversion kinetics and adsorption capacity. In a pouch cell configuration with lean electrolyte conditions (∼5 µL mg-1), the g-C3N4-Mx/S cathode exhibited excellent rate performance, delivering ∼1061 mA h g-1 at C/8 and retaining ∼773 mA h g-1 after 190 cycles with a Coulombic efficiency (CE) of 92.7%. The battery maintained a discharge capacity of 680 mA h g-1 even at 1.25 C. It operated reliably at an elevated sulfur loading of 5.9 mg cm-2, with an initial discharge capacity of ∼900 mA h g-1 and a sustained CE of over 83% throughout 190 cycles. Postmortem XPS and EIS analyses elucidated charge-discharge cycle-induced changes, highlighting the potential of this heterostructured cathode for commercial garnet LSB development.

Silver Doped Graphitic Carbon Nitride for the Enhanced Photocatalytic Activity Towards Organic Dyes.

Recently, graphitic carbon nitride has been investigated as a promising photocatalyst for organic dye degradation application. In this study, a facile strategy to synthesise silver nanoparticles (AgNPs) doped graphitic carbon nitride (GCN-Ag) has been reported. The characterisation study of the asprepared samples was performed using various analytical techniques. The X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) revealed that the structure of pure graphitic carbon nitride (GCN-Pure) partly changed on the addition of the AgNPs. The diffused reflectance spectra (DRS) unveiled a significant red shift in the absorption edge of GCN-Ag. The scanning electron microscopy (SEM) analysis revealed that the morphological aspects of GCN-Pure changed on the addition of AgNPs. Further the as-prepared samples have been compared for their degradation activity towards organic dye pollutants including methylene blue, crystal violet and rose bengal. The phenomenon of the better separation of photogenerated charge carriers was attributed to the better photoactivity in the case of GCN-Ag than GCN-Pure. In addition to it the reusability experiment of GCN-Ag revealed that the catalyst remained highly stable after the three cyclic runs of photodegradation experiment.

Photocatalytic Activity of Green Synthesized AgCl Nanoparticles Towards E. coli Bacteria.

The present work focus on plant extracts mediated synthesis of silver chloride nanoparticles (AgCl-NPs). The AgCl-NPs were synthesized using the plant leaf extract of Origanum-majorana by one step green synthesis method. The characterization of as prepared AgCl-NPs were done by various analytical techniques such as UV-Vis spectroscopy, X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). The morphology and composition of AgCl-NPs was confirmed by scanning electron microscopy analysis (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis, respectively. Further, photocatalytic activity of as prepared AgCl-NPs observed by elimination of E. coli bacteria from contaminated water under solar light irradiation and it was observed that AgCl-NPs possess a good photocatalytic activity performance against E. coli bacteria.

Au-TiO2-Loaded Cubic g-C3N4 Nanohybrids for Photocatalytic and Volatile Organic Amine Sensing Applications.

A green and efficient approach for efficient nanohybrid photocatalysts in extending the light response to the visible spectrum is a hot research topic in sustainable energy technologies. In this work, novel Au-TiO2@m-CN nanocomposite was synthesized using hard template of cubic ordered mesoporous KIT-6 via the nanocasting process. The as-prepared Au-TiO2@m-CN nanohybrids exhibit enhanced photocatalytic activities with improved stability and reusability using methyl orange dye. The enhanced photocatalytic performance is a result of the conjugated effect of catalytic active Au and TiO2 nanoparticles supported on highly efficient visible light sensitizer, graphitic carbon nitride (m-CN or g-C3N4), and ordered mesoporous morphology. Besides, the sensing performance of Au-TiO2@m-CN nanohybrids was also tested for the detection of amine gases, wherein a significant response was reported for triethylamine at low operating temperatures. This study reveals a simple and scalable methodology to design and develop next generation of layered mesoporous materials for multifunctional applications.

Aero-gel assisted synthesis of anatase TiO2 nanoparticles for humidity sensing application.

Aero-gel based one-pot synthesis of anatase phase TiO2 nanoparticles having a high surface area of 125 m2 g-1 has been reported in this work. The humidity sensing perfomance of the obtained porous TiO2 nanoparticles exhibits a quick response (2 s) and fast recovery (1.5 s), negligible hysteresis (<1%) and good stability in the 11-98%RH range. The relationship between %RH and resistance was found to be linear while the sensitivity increases with increase in %RH.

Plasmonic DNA hotspots made from tungsten disulfide nanosheets and gold nanoparticles for ultrasensitive aptamer-based SERS detection of myoglobin.

A nanohybrid mediated SERS substrate was prepared by in-situ synthesis and assembly of gold nanoparticles (AuNPs) on exfoliated nanosheets of tungsten disulfide (WS2) to form plasmonic hotspots. The nanohybrid surface was functionalized with specific aptamers which imparted high selectivity for the cardiac marker myoglobin (Mb). The fabricated aptasensor was read by SERS using a 532 nm laser and demonstrated significant signal enhancement, and this allowed Mb to be determined in the 10 f. mL-1 to 0.1 µg mL-1 concentration range. The study presents an approach to synergistically exploit the unique chemical and electromagnetic properties of both WS2 and AuNPs for many-fold enhancement of SERS signals. Graphical abstract Schematic presentation of a nanohybrid-mediated SERS substrate prepared by in-situ assembly of gold nanoparticles (AuNPs) reduced on exfoliated nanosheets of tungsten disulfide (WS2) to form plasmonic hot spots. Specific aptamers immobilized on the SERS surface impart high sensitivity and selectivity for the cardiac marker myoglobin (Mb).

Near-Room-Temperature Ethanol Detection Using Ag-Loaded Mesoporous Carbon Nitrides.

Development of room-temperature gas sensors is a much sought-after aspect that has fostered research in realizing new two-dimensional materials with high surface area for rapid response and low-ppm detection of volatile organic compounds (VOCs). Herein, a fast-response and low-ppm ethanol gas sensor operating at near room temperature has been fabricated successfully by utilizing cubic mesoporous graphitic carbon nitride (g-CN, commonly known as g-C3N4), synthesized through template inversion of mesoporous silica, KIT-6. Upon exposure to 50 ppm ethanol at 250 °C, the optimized Ag/g-CN showed a significantly higher response (R a/R g = 49.2), fast response (11.5 s), and full recovery within 7 s in air. Results of sensing tests conducted at 40 °C show that the sensor exhibits not only a highly selective response to 50 ppm (R a/R g = 1.3) and 100 ppm (R a/R g = 3.2) of ethanol gas but also highly reversible and rapid response and recovery along with long-term stability. This outstanding response is due to its easily accessible three-dimensional mesoporous structure with higher surface area and unique planar morphology of Ag/g-CN. This study could provide new avenues for the design of next-generation room-temperature VOC sensors for effective and efficient monitoring of alarming concern over indoor environment.

Cubic mesoporous Ag@CN: a high performance humidity sensor.

The fabrication of highly responsive, rapid response/recovery and durable relative humidity (%RH) sensors that can precisely monitor humidity levels still remains a considerable challenge for realizing the next generation humidity sensing applications. Herein, we report a remarkably sensitive and rapid %RH sensor having a reversible response using a nanocasting route for synthesizing mesoporous g-CN (commonly known as g-C3N4). The 3D replicated cubic mesostructure provides a high surface area thereby increasing the adsorption, transmission of charge carriers and desorption of water molecules across the sensor surfaces. Owing to its unique structure, the mesoporous g-CN functionalized with well dispersed catalytic Ag nanoparticles exhibits excellent sensitivity in the 11-98% RH range while retaining high stability, negligible hysteresis and superior real time %RH detection performances. Compared to conventional resistive sensors based on metal oxides, a rapid response time (3 s) and recovery time (1.4 s) were observed in the 11-98% RH range. Such impressive features originate from the planar morphology of g-CN as well as unique physical affinity and favourable electronic band positions of this material that facilitate water adsorption and charge transportation. Mesoporous g-CN with Ag nanoparticles is demonstrated to provide an effective strategy in designing high performance %RH sensors and show great promise for utilization of mesoporous 2D layered materials in the Internet of Things and next generation humidity sensing applications.