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Flexible electronic gas sensors working at room temperature have acquired enormous attention in recent years due to their suitability to be integrated into various wearable electronic products. In ...

Herein, we report the formation of well-aligned ultrathin films of polyaniline-functionalized multiwalled carbon nanotubes (PANI@MWCNTs) with a high orientational order over a macroscopic area by L...

A comparative analysis of NO2 gas sensing performances of geometry-controlled Au decorated ZnO heterojunction nanostructures (nanospheres, nanorods, ultra-long nanorods and nanofibers) has been dem...

Interaction of water on heterogeneous nonwetting interfaces has fascinated researchers' attention for wider applications. Herein, we report the evolution of hierarchical micro-/nanostructures on superhydrophobic pseudoboehmite surfaces created from amorphous Al

Electrospun carbon nanofibers (CNF) with surface-anchored bimetallic gold–platinum nanoislands (CNFs@Au–Pt NIs) have been effectively developed by electrospinning and chemical reduction methods, an...

Unique phosphorous doped onion-like carbon nanostructures (P-OLCs) with superior surface properties have been synthesized through a temperature and pressure controlled thermal decomposition method. The substitutional doping of phosphorous in OLCs nanostructures could facilitate the charge transfer during ammonia gas sensing. Presence of polar metaphosphates/phosphonate species in the active sites of highly crystalline P-OLCs due to interstitial doping of oxygen incorporated with substitutionally doped phosphorous atoms significantly enhanced the sensitivity with fast response and recovery characteristics (2.8 s and 4.5 s) towards NH3 at room temperature. Further, ammonia gas adsorption kinetics in OLCs and P-OLCs have been meticulously investigated which revealed the faster adsorption rate in P-OLCs (2.17 x 10-7 Ω-1s-1) compared to pristine OLCs (8.599 x 10-8 Ω-1s-1). This method can widely open up the feasibility to induce enhanced surface activity (phosphorus-containing groups allows the access of oxyge...

Herein, we demonstrate a novel approach for development of TiO2 grafted 2D-TiC nanosheets (TiO2@2D-TiC) based room temperature operable, flexible ethanol gas sensor. The homogeneous distribution, unique composition, and crystalline microstructure of TiO2 nanoparticles grafted 2D-TiC nanosheets have been found to enhance the surface reactivity and efficiency of its transducer–receptor functions. The electron–hole recombination at the TiO2/2D-TiC interfaces offered superior sensor performance with fast response and recovery times. Moreover, TiO2@2D-TiC nanosheets based flexible sensor exhibited high selectivity toward trace-level ethanol gas (10 ppb–60 ppm) with extremely low noise-to-signal ratio and excellent stability. The results suggest that the development of low-cost flexible sensors based on TiO2@2D-TiC nanosheets could be applied for potential applications, such as printed/wearable electronics, biomedical sector and environmental monitoring.

Defect engineering in n-type undoped metal oxides is a great challenge compared to the often-studied surface oxygen vacancies. The present investigation unravels new insights toward defect chemistry and defect engineering in anatase TiO2 nanoparticles. It is demonstrated that using the rapid cooling process, high concentration of Ti3+ interstitials, and lattice oxygen vacancies can be easily introduced in undoped metal oxides. The structural disorders in anatase TiO2 nanoparticles synthesized under two different argon-annealing processes have been comprehensively investigated using spectroscopy and electron microscopic analysis. Though excess of interstitial Ti3+ ions with one unpaired 3d electron in quenched TiO2 introduces local magnetic moments, they could be antiferromagnetically coupled via lattice Ti4+ ions, which limit the overall magnetic moment of the quenched materials. Lattice contraction was also found to enhance the ferromagnetic coupling between the defect complexes (Ti3+–F+ center) which he...

Herein, we report a facile approach for the synthesis of TiO2 nanoparticles tethered on 2D mixed valent vanadium oxide (VOx/TiO2) nanoflakelets using a thermal decomposition assisted hydrothermal method and investigation of its temperature-independent performance enhancement in oxygen-sensing properties. The material was structurally characterized using XRD, TEM, Raman, DSC, and XPS analysis. The presence of mixed valent states, such as V2O5 and VO2 in VOx, and the metastable properties of VO2 have been found to play crucial roles in the temperature-independent electrical conductivity of VOx/TiO2 nanoflakelets. Though pristine VOx exhibited characteristic semiconductor-to-metal transition of monoclinic VO2, pure VOx nanoflakelets exhibited poor sensitivity toward sensing oxygen. VOx/TiO2 nanoflakelets showed a very low temperature coefficient of resistance above 150 °C with improved sensitivity (35 times higher than VOx for 100 ppm) toward oxygen gas. VOx/TiO2 nanoflakelets exhibited much higher response,...

Charge transport and adsorption kinetics of wet-chemically synthesized CuO nanocuboids have been explored. The growth direction of CuO nanocuboids was found to be (111) plane, which exhibited predominant surface catalytic activity toward the dissociation of H2S and O2. Temperature-dependent adsorption studies revealed the adsorption kinetics of (111) grown p-type CuO nanocuboids toward H2S gas. Adsorption of oxygen (O2) on the CuO (111) surface resulted in the formation of ionosorbed O2¯ species, which increased the hole density and enhanced the surface conductivity of CuO nanocuboids. H2S molecules were found to interact well with CuO (111) surface, donating electrons to the material and reducing the hole-accumulation layer width. Investigation of electrical characteristics of p-type CuO nanocuboids revealed absence of any structural phase transitions under H2S environment. The H2S sensing mechanism was found to be associated with local suppression/expansion of the hole-accumulation layer of p-CuO nanocu...