Amit Sanger

In today's era, the rise of flexible, biodegradable, and micro‐energy storage devices represents the next frontier of sustainable electronics. Despite promising conductivity, carbon nanotube (CNT)‐based supercapacitors display modest capacitance and compromised rate performance due to densely packed layers or diffusion paths of ions. To make a promising and sustainable device, we synthesized CNT‐inks with enhanced and improved intertubular spacing. Herein, we report improved ion diffusion paths and enhanced interwall spacing by insertion of ions. For the scalable production of microsupercapacitors (MSCs), the Li‐ion modified CNT‐ink was further processed via screen printing. Coupled with the engineered electrode architecture and wide electrochemical window of bis(trifluoromethane)sulfonamide lithium (LiTFSI) water‐in‐salt (WIS) electrolyte, the device with limited interdigitated‐electrode (IDE) fingers achieved a high areal capacitance (42 mF/cm ² ) and excellent cyclic durability (∼95% after 20,000 cycles). Additionally, Kelvin‐probe force microscopy (KPFM) revealed dynamic surface potential modulation, directly evidencing Fermi level tuning through Li ⁺ ion adsorption. Notably, the MSC also performed with commendable electrochemical behavior even at ultra‐low temperatures down to −60°C and demonstrated effective power generation at high humidity. Also, we tested device reproducibility with remarkable performance and excellent flexibility. These outstanding performances underscore their strong potential for next‐generation wearable and environmentally adaptive electronics.

Chemiresistive sensors based on graphene derivatives and metal oxides continue to attract attention, yet achieving rapid and selective room‐temperature detection remains challenging due to sluggish surface kinetics and limited understanding of interfacial interactions. Here, we report a Bi ₂ MoO ₆ /reduced graphene oxide (rGO) heterostructure synthesized via hydrothermal synthesis and integrated onto interdigitated electrodes via blade coating. The device delivers outstanding ethanol sensing at 27°C, exhibiting a ∼16‐fold enhancement over pristine Bi ₂ MoO ₆ at 100 ppm, rapid 13/18 s response–recovery dynamics, a detection limit of 1.6 ppm, and excellent reproducibility and long‐term stability. A portable prototype module incorporating this sensor further demonstrates reliable real‐time ethanol monitoring, highlighting its practical applicability for environmental and breath analysis. To elucidate the origin of the unusual sensing behavior, we combine density functional theory (DFT) calculations with COMSOL‐based kinetic modeling. Despite its lowest adsorption energy among the tested analytes, ethanol induces the largest conduction‐band perturbation at the interface, whereas kinetic simulations reveal that weak adsorption accelerates adsorption–desorption turnover, thereby enabling frequent charge‐transfer events within the sensing timescale. This cooperative interplay between weak binding and dynamic interfacial modulation explains the exceptional selectivity and ultrafast response. These results establish Bi ₂ MoO ₆ /rGO as a mechanism‐guided platform for high‐performance room‐temperature gas sensing device development.

Heat is a plentiful energy source available within us and in our surroundings, yet it is still underutilized and wasted. Capturing even a small fraction of this energy provides an opportunity to contribute to an eco‐friendly and sustainable society. Although traditional solid‐state inorganic semiconductor materials have led the research stage of thermoelectric (TE) energy conversion, carbon‐based hybrid materials and hydrogels provide an emerging TE platform for wearable, flexible, and low‐temperature energy harvesting devices for powering sensors. These materials have expanded the application of these thermoelectric materials beyond heat‐to‐electrical energy conversion to power various smart devices for use in healthcare monitoring and environmental remediation. This review is divided into three main categories. First, this work focuses on the fundamentals of TE generators and their classifications. In the second section, a thorough discussion of integrated sensor fabrication, including single and hybrid systems and their performance matrices, is given. Special attention is given to self‐healing materials that improve device longevity and achieve environmental sustainability. Section three discusses the incorporation of machine learning (ML) techniques into TE‐powered sensors. By emphasizing the latest discoveries to tabulate the entire range of thermoelectric‐powered sensors, this review bridges materials science, wearable technologies, and advanced engineering.

This work presents a room-temperature (RT) NO₂ gas sensor based on cotton-modified LaFeO₃ (CLFO) combined with MXene. LaFeO₃ (LFO), CLFO, and CLFO/MXene composites were synthesized via a hydrothermal method. The fabricated sensor, utilizing MXene/CLFO, exhibits a p-type behavior and fully recoverable sensing capabilities for low concentrations of NO₂, achieving a higher response of 14.2 times at 5 ppm. The sensor demonstrates excellent performance with a response time of 2.7 s and a recovery time of 6.2 s, along with notable stability. The sensor's sensitivity is attributed to gas interactions on the material's surface, adsorption energy, and charge-transfer mechanisms. Techniques such as in situ FTIR (Fourier transform infrared) spectroscopy, GC-MS (gas chromatography-mass spectroscopy), and near-ambient pressure X-ray photoelectron spectroscopy were employed to verify gas interactions and their byproducts. Additionally, finite-difference time-domain simulations were used to model the electromagnetic field distribution and provide insight into the interaction between NO₂ molecules and the sensor surface at the nanoscale. A prototype wireless IoT (Internet of Things)-based NO₂ gas leakage detection system was also developed, showcasing the sensor's practical application. This study offers valuable insight into the development of room-temperature NO₂ sensors with a low detection limit.

In this study MgPd alloy thin films were deposited on a glass substrate using DC/RF magnetron sputtering technique with varying sputtering power (30-60W) of Pd target to achieve different compositions of alloy. X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) analyses provides the crystalline structure and elemental composition of the MgPd alloy thin films, respectively. The surface morphology study through Field Emission Scanning Electron Microscopy (FE-SEM) reveals nano-flakes. Gas sensing study reveals that the sensitivity of the Mg ₆₅ Pd ₃₅ alloy thin film sensor is 3.41% for 500 ppm and 13% for 1 bar of hydrogen (H₂) at room temperature. The response/recovery times of the sensor are 5 s/3 min and 85 s/6 min for 1 bar H ₂ gas and 500 ppm H ₂ , respectively. A remarkable selectivity towards the H ₂ gas is observed in comparison to other gases such as CO, NO ₂ and NH ₃ . Long-term stability was observed even with increased Pd composition over multiple hydrogenation/dehydrogenation cycles. These findings suggest that Pd-capped MgPd alloy thin films are promising for the applications of highly durable, selective, cost-effective, and room-temperature hydrogen gas sensors.

This study presents nanostructured composite Bi₂MoO₆/MXene heterostructure by using hydrothermal method for photodegradation of the congo-red dye and also for energy storage devices. X-ray diffractometer (XRD), High Resolution Transmission Electron Microscopy (HRTEM), Field emission scanning electron microscope (FESEM) and X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) were performed to examine the structural properties along with surface area and porosity of the material. Due to addition of MXene the larger surface area and improved pore size help to quickly break down additional organic pollutants by adsorbing them. The band gap of Bi₂MoO₆/MXene nanostructured composite reduced to 2.4 eV suggesting transfer of electrons from VB to CB. Bi₂MoO₆/MXene exhibits a high (92.3%) photocatalytic degradation rate for a duration of 16 min which was verified using UV-visible spectroscopy, also scavenger test was conducted to ascertain the reactive agent along with the degradation pathway was confirmed by LCMS. Elemental content was also established by using inductively coupled plasma mass spectrometry (ICP-MS). For estimating energy storage capacity cyclic voltammetry (CV) was performed. It was observed Bi₂MoO₆/MXene nanostructured composite electrodes had specific capacitance of 642.91Fg^− 1, power density of 1.24 kWkg^− 1, and energy density of 22.32 Whkg^− 1 at a current density of 5Ag^− 1 also it exhibited 64.42% capacity retention having current density 20 Ag^− 1 throughout 10,000 Galvanostatic charge discharge (GCD) cycles. High electrical conductivity of Bi₂MoO₆/MXene electrode was again examined by Electrochemical impedance spectroscopy (EIS). These findings demonstrate the potential of Bi₂MoO₆/MXene nanostructured composites in both photodegradation and energy storage applications.

The direct conversion of solar energy into clean fuels has emerged as an effective approach for future energy production and addressing environmental challenges. This research focuses on the synthesis of BiOCl using a straightforward hydrothermal method with Ag modification achieved through green synthesis. These materials were applied to enhance photocatalytic processes and hydrogen (H₂) evolution. Comprehensive characterization of the synthesized photocatalysts was performed by using techniques, such as XRD, SEM, BET, XPS, and UV-vis spectroscopy. The Ag/BiOCl composite demonstrated impressive photocatalytic performance, achieving degradation rates of 96% for RhB, 87.7% for TC, and 85% for HQ under 18 min of solar irradiation. Additionally, a high mineralization rate of 92% was observed through Total Organic Carbon (TOC) analysis. Furthermore, the Ag/BiOCl composite exhibited a significant H₂ evolution rate of 565 μmol g^-1 h^-1, which is nearly double that of pure BiOCl. The interaction between Ag and BiOCl was found to enhance the generation of O₂- radicals, as confirmed by radical trapping experiments, with the underlying mechanism elucidated using LC-HRMS. The nanoparticles also demonstrated excellent degradation of industrial waste, highlighting the potential of Ag/BiOCl for use in the purification and sterilization of industrial effluents.