Stage Lysgaard (doublebull95)
In this study the optical band gap of SiC and Si varied from ~2.92 to ~2.40 eV and from ~2.00 to ~1.79 eV, as the size of the SiC and Si nanocrystals varied with respect to the heating temperature and isothermal holding time, respectively.The presence of malachite green dye in wastewater has a great negative impact on the environment. At present, industrial wastewater is treated using adsorption, electrolysis and membrane separation, among which the adsorption method is the most widely used wastewater treatment. In this study mesoporous silica nanoparticles (MSNs) were prepared using the sol-gel method and modified with the natural polymer urushiol (U) to obtain MSN@Us, which have a core-shell structure. This is the first use of urushiol in dye adsorption. The structures and chemical properties of the MSNs and MSN@Us were characterized. The adsorption of malachite green by the MSNs and MSN@Us showed that the adsorption rate of MSN@Us was higher than that of MSNs, with an adsorption rate greater than 90%. This study provides a new research direction for the use of urushiol in the treatment of contaminated wastewater.Compared with bulk material-based sensors, functional sensors fabricated with nanomaterials have many advantages, such as high sensitivity, multifunctional integration, low power-dissipation, and low cost. Black phosphorus (BP) is a two-dimensional (2D) crystal material, which has a higher molecular adsorption energy, tunable direct band gap, high carrier mobility, ambipolar characteristics, and high current on/off ratio. In this paper, BP bulk was ground into powder, and then the powder was dispersed in dimethylformamide (DMF) to obtain two-dimensional BP nanosheets solution. Afterwards, the black phosphorus nanosheets and H₂PtCl6 solution were mixed to obtain the Pt functionalized BP nanocomposite by one-step reduction method. Pt nanoparticles were dispersed on the surface of BP nanosheets with highly uniform size. The Pt functionalized BP nanocomposite exhibited a high response of 2.19 to 10 ppm NOx in a short period of 1.93 s at room temperature. The detection limit was as low as 30 ppb. The Pt functionalized BP nanocomposite will be useful for precise detection of NOx.Air pollution is a big concern as it causes harm to human health as well as environment. NO₂ can cause several respiratory diseases even in low concentration and therefore an efficient sensor for detecting NO₂ at room temperature has become one of the priorities of the scientific community. Although two dimensional (2D) materials (MoS₂ etc.) have shown potential for NO₂ sensing at lower temperatures, but these have poor desorption kinetics. However, these limitations posed by slow desorption can be overcome, if a material in the form of a p-n junction can be suitably employed. In this work, ~150 nm thick SnSe₂ thin film has been deposited by thermally evaporating in-house made SnSe₂ powder. The film has been studied for its morphological, structural and gas sensing applications. The morphology of the film showed that the film consists of interconnected nanostructures. Detailed Raman studies further revealed that SnSe₂ film had 31% SnSe. The SnSe-SnSe₂ nanostructured sensor showed a response of ~112% towards 5 ppm NO₂ at room temperature (30 °C). The response and recovery times were ~15 seconds and 10 seconds, respectively. Limit of detection for NO₂ was in sub-parts per million (sub-ppm) range. The device demonstrated a better response towards NO₂ compared to NH₃, CH₄, and H₂. The mechanism of room temperature fast response, recovery and selective detection of NO₂ independent of humidity conditions has been discussed based on physisorption, charge transfer, and formation of SnSe-SnSe₂ (p-n) nano-junctions. Depositing a nanostructured film consisting of nano-junctions using an industrially viable thermal evaporation technique for sensing a very low concentration of NO₂ is the novelty of this work.A cold roll-bonding process was applied to fabrica
