Fast and selective detection of volatile organic compounds using a novel pseudo spin-ladder compound CaCu2O3

A novel pseudo spin-ladder CaCu2O3 compound (2-leg) based conductometric gas sensor has been proposed, for the first time, for the detection of volatile organic compounds (VOCs); (a) the proposed reaction mechanism in air, and (b) in the presence of acetone and ethanol

Monitoring of Chemical Risk Factors for Sudden Infant Death Syndrome (SIDS) by Hydroxyapatite-Graphene-MWCNT Composite-Based Sensors

Sensing properties of chemical sensors based on ternary hydroxyapatite-graphene-multiwalled carbon nanotube (HA-GN-MWCNT) nanocomposite in the detection of chemical substances representing risk factors for sudden infant death syndrome (SIDS), have been evaluated. Characterization data of the synthesized composite have shown that the graphene-MWCNT network serves as a matrix to uniformly disperse the hydroxyapatite nanoparticles and provide suitable electrical properties required for developing novel electrochemical and conductometric sensors. A HA-GN-MWCNT composite-modified glassy carbon electrode (HA-GN-MWCNT/GCE) has been fabricated and tested for the simultaneous monitoring of nicotine and caffeine by cyclic voltammetry (CV) and square wave voltammetry (SWV), whereas a HA-GN-MWCNT conductive gas sensor has been tested for the detection of CO2 in ambient air. Reported results suggest that the synergic combination of the chemical properties of HA and electrical/electrochemical characteristics of the mixed graphene-MWCNT network play a prominent role in enhancing the electrochemical and gas sensing behavior of the ternary HA-GN-MWCNT hybrid nanostructure. The high performances of the developed sensors make them suitable for monitoring unhealthy actions (e.g., smoking, drinking coffee) in breastfeeding women and environmental factors (bad air quality), which are associated with an enhanced risk for SIDS

Synthesis of Silver and Gold Nanoparticles from Rumex roseus Plant Extract and Their Application in Electrochemical Sensors

The room-temperature synthesis of silver (AgNPs) and gold (AuNPs) nanoparticles from aqueous solution of AgNO3 and HAuCl4 respectively, using Rumex roseus (RR) plant extract as a reducing agent, is reported here for the first time. The nanoparticles obtained were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The formation of nanoparticles with spherical-shaped morphology was verified by TEM and confirmed by UV-Vis spectroscopy through the analysis of Ag and Au plasmon resonance peak and DLS measurements. New electrochemical sensors have been developed by employing the synthesized Ag and Au nanoparticles as modifiers of glassy carbon electrode (GCE) and screen-printed carbon electrode (SPCE), respectively. The AgNPs-modified GCE was investigated for the electrochemical determination of hydrogen peroxide (H2O2). Further enhancement of electrochemical performances was obtained using a nanocomposite made of AgNPs and reduced graphene oxide (rGO)-modified GCE. The AuNPs-SPCE sensor was instead tested in the electrochemical sensing of riboflavin (RF). To our knowledge, this is the first paper reporting Rumex roseus plant extract as a source for the synthesis of metal nanoparticles and their use for developing simple, sensitive and reliable electrochemical sensors for H2O2 and RF

Role of chicken fat waste and hydrogen energy ratio as the potential alternate fuel with nano-additives: Insights into resources and atmospheric remediation process

The main focus of the study was to witness the effects of chicken waste-based biodiesel blends along with constant hydrogen injection in a modified diesel engine. Furthermore, the nanoparticle multiwall carbon nanotubes (MWCNT) effects on the engine efficiency were also examined. A series of tests was conducted in the single cylinder, water cooled engine fuelled with diesel, CB100N, CB10N, CB30N, and CB50N. Throughout the entire run, constant hydrogen injection of 5 LPM has been maintained. The parameters such as brake thermal efficiency, brake specific fuel consumption, heat release rate and the emissions of different pollutants were determined for a variety of engine speeds. ASTM standards were applied to measure the viscosity, density and calorific value. From the reported findings, it was clear that the addition of the chicken waste biodiesel could be a sustainable substitute for the existing fossil fuels. Although the emission of the pollutants was dropped significantly, there was a massive drop in the BTE values. To compensate such shortage of power, the biodiesel was dispersed with MWCNT at the concentration of 80 ppm. Compared to the regular biodiesel, MWCNT inclusion increased the BTE by 14%. Further, the consumption of the fuel was also reduced marginally. Considering the pollutants, the catalytic activity of the MWCNT reduced the emissions of CO, NOx, and HC at various engine speeds. Besides, 10% reduction in NOx had been reported at lower engine speeds and was reduced to 8% at higher speed regimes. Compiling all together, increasing the concentration of the biodiesel blends obviously reduced the performance values and however, there was a great advantage in terms of the emission magnitudes irrespective of the engine operating conditions. © 2022 Elsevier Inc.King Saud University, KS

Utilization of enriched hydrogen blends in the diesel engine with MgO nanoparticles for effective engine performance and emission control

The influence of hydrogen on the diesel engine has been examined in this study. In addition, the impact of MgO nanoparticles was also analysed by conducting a series of tests on samples such as Diesel (100 % diesel), DN (Diesel-50 ppm MgO), H1N (10 % Hydrogen-50 ppm MgO) and H2N (20 % Hydrogen-50 ppm MgO). Hydrogen was injected through intake manifold at the volume of 10 % and 20 %. Nanoparticles were dispersed using the ultrasonication techniques to accrue stable suspension. The experiments were conducted between 6 N-m to 24 N-m loads on a four-stroke single cylinder engine. The parameters such as brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and heat release rate (HRR) were assessed. In addition to the performance and combustion, the environmental impact of the test blends was also analysed by examining the exhaust with a gas analyser. From the series of tests, it was evident that hydrogen enrichment in the test blends reported lower levels of emissions compared to neat diesel. The formation of the hydrocarbons (HC), nitrogen of oxides (NOx), carbon monoxide (CO), and carbon dioxide (CO2) was reduced due to the drop in the carbon atoms and enriched oxygen content in the combustion chamber. With regard to the performance, the hydrogen enriched nanoparticle blends reported peak BTE (37 %) and HRR (75 J/deg) than the other test blends. By assessing all the results, the addition of hydrogen is a potential option to reduce the environmental impact created by the fossil fuel without forfeiting the engine efficiency. © 2022 Elsevier LtdKing Saud University, KSU; Chiang Mai University, CMU: RSP-2022/23

Metal-Oxide Based Nanomaterials: Synthesis, Characterization and Their Applications in Electrical and Electrochemical Sensors

Pure, mixed and doped metal oxides (MOX) have attracted great interest for the development of electrical and electrochemical sensors since they are cheaper, faster, easier to operate and capable of online analysis and real-time identification. This review focuses on highly sensitive chemoresistive type sensors based on doped-SnO2, RhO, ZnO-Ca, Smx-CoFe2−xO4 semiconductors used to detect toxic gases (H2, CO, NO2) and volatile organic compounds (VOCs) (e.g., acetone, ethanol) in monitoring of gaseous markers in the breath of patients with specific pathologies and for environmental pollution control. Interesting results about the monitoring of biochemical substances as dopamine, epinephrine, serotonin and glucose have been also reported using electrochemical sensors based on hybrid MOX nanocomposite modified glassy carbon and screen-printed carbon electrodes. The fundamental sensing mechanisms and commercial limitations of the MOX-based electrical and electrochemical sensors are discussed providing research directions to bridge the existing gap between new sensing concepts and real-world analytical applications

Assessing the effects of ammonia (NH3) as the secondary fuel on the combustion and emission characteristics with nano-additives

Ammonia is a promising alternative to replace the non-renewable fossil fuels. The present work offers the detailed evaluation of ammonia suitability in the diesel engine and how it is affecting the primary properties of the diesel engine. A series of tests was conducted on the test samples such as diesel, B20, B20N, B20A5 and B20A10 across various engine loading conditions. Two different ammonia energy ratios of 5 L/min and 10 L/min have been utilized. In addition to ammonia, the role of nanoparticles was analyzed and compared how far they can be competitive to the green ammonia fuel. 75 ppm of TiO2 nanoparticles was dispersed with Chlorella vulgaris microalgae biodiesel blends using ultrasonication. Ammonia was injected as the secondary fuel via air intake. Based on the results, adding ammonia in the diesel engine reduced the brake thermal efficiency of the engine. There was a drastic drop in the brake thermal efficiency that has been reported across various loads. Nevertheless, biodiesel blends with nanoparticles reported peak thermal efficiency due to the enhanced cetane number and calorific value of the fuel. On contrary, the brake specific fuel consumption of B10A and B20A was decreased compared to the other blends. As the ammonia concentration increased, both the peak cylinder pressure and heat release rates were higher. Due to the addition of ammonia, NOx emission was higher due to the higher cylinder temperature. On the other hand, the emissions of carbon dioxide, carbon monoxide and hydrocarbons were reduced for all cases compared to neat diesel. © 2022Jiangsu Agricultural Science and Technology Innovation Fund, JASTIF: CX(22)2045, RSP-2022/257; King Saud University, KS

Spirulina microalgae blend with biohydrogen and nanocatalyst TiO2 and Ce2O3 as step towards emission reduction: Promoter or inhibitor

Extensive use of fossil fuels is the main cause for global warming. Burning of fossil fuels increases the air pollution which leads to adverse human health effects. Biodiesel is one the promising source of the energy to replace fossil fuel. The current study focused on one of the most sustainable microalgae biodiesel blends in the diesel engine. Further, the nanoparticles such as TiO2 and Ce2O3 were sonicated with the blends at the rate of 50 ppm to increase the brake thermal efficiency with least production of the pollutants. In addition to above, the hydrogen is also used as the secondary fuel to enhance the performance and combustion characteristics of the spirulina biodiesel. The constant hydrogen flow rate of 10 L/min was maintained throughout the study. Compared to the diesel fuel, biodiesel blends reported higher BTE due to the oxygenated additives and hydrogen addition. The maximum thermal efficiency for blend B30TH was found to be 29.5 % and minimum specific fuel consumption has been obtained for B30CH at maximum brake power conditions. In all test conditions, the biodiesel blends with hydrogen reported higher in-cylinder pressure and heat release rate. With regard to the emission, adding the biodiesel blends increases the combustion rates which leads to the reduction of accumulation of pollutants such as carbon monoxide, carbon dioxide, hydrocarbons, nitrogen of oxides and smoke. Among the various blends B20CH reported a massive reduction in the emission than B20TH.Van Lang University, Vietnam; King Saud University, Riyadh, Saudi Arabia [RSP-2021/385