Aerosol-Assisted CVD-Grown PdO Nanoparticle-Decorated Tungsten Oxide Nanoneedles Extremely Sensitive and Selective to Hydrogen

We report for the first time the successful synthesis of palladium (Pd) nanoparticle (NP)-decorated tungsten trioxide (WO3) nanoneedles (NNs) via a two-step aerosol-assisted chemical vapor deposition approach. Morphological, structural, and elemental composition analysis revealed that a Pd(acac)2 precursor was very suitable to decorate WO3 NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H2) gas sensor (sensor response peaks at 1670 at 500 ppm of H2) with low operating temperature (150 °C). The response of decorated NNs is 755 times higher than that of bare WO3 NNs. Additionally, at a temperature near that of the ambient temperature (50 °C), the response of this sensor toward the same concentration of H2 was 23, which is higher than that of some promising sensors reported in the literature. Finally, humidity measurements showed that PdO/WO3 sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO3 sensors. The addition of PdO NPs helps to minimize the effect of ambient humidity on the sensor response

Tin(IV) complexes with salen type Schiff base:synthesis, spectroscopic characterization, crystal structure, antibacterial screening and cytotoxicity

A series of six tin(IV) complexes [SnCl2(L) (I), Me2Sn(L) (II), Bu2Sn(L) (III), Ph2Sn(L) (IV), Oct2Sn(L) (V), BuSnCl(L) (VI)] derived from N,N'-bis(2-hydroxy-1-naphthylidene)-1,2-diaminobenzene [LH2] have been synthesized. The obtained compounds were characterized by elemental analysis, mass spectrometry, FT-IR and NMR (1H, 13C) spectroscopy. The crystal structures of compounds (IV) and (VI) have also been determined by single crystal X-ray analysis (CIF files CCDC nos. 856596 (IV) and 856595 (VI)). The study revealed that the complexes exist as discrete monomeric species and the tin atom is hexa-coordinated in a distorted octahedral geometry. The two phenyl groups in compound (IV) are at trans-positions. Similarly, in complex (VI) the butyl and chloro groups also adopt trans-orientation. The in vitro antibacterial screening and cytotoxicity investigations revealed that the biological activities significantly depend upon the alkyl or others groups present on tin atom. Most of the tin(IV) complexes are active against Escherichia coli and highest activity is shown by complex (IV) against Bacillus subtilis. Furthermore, complex (IV) has also demonstrated the highest cytotoxicity against brine shrimp with LD50 value 0.858 μg/mL

Aerosol-Assisted CVD-Grown PdO Nanoparticle-Decorated Tungsten Oxide Nanoneedles Extremely Sensitive and Selective to Hydrogen

We report for the first time the successful synthesis of palladium (Pd) nanoparticle (NP)-decorated tungsten trioxide (WO₃) nanoneedles (NNs) via a two-step aerosol-assisted chemical vapor deposition approach. Morphological, structural, and elemental composition analysis revealed that a Pd­(acac)₂ precursor was very suitable to decorate WO₃ NNs with uniform and well-dispersed PdO NPs. Gas-sensing results revealed that decoration with PdO NPs led to an ultrasensitive and selective hydrogen (H₂) gas sensor (sensor response peaks at 1670 at 500 ppm of H₂) with low operating temperature (150 °C). The response of decorated NNs is 755 times higher than that of bare WO₃ NNs. Additionally, at a temperature near that of the ambient temperature (50 °C), the response of this sensor toward the same concentration of H₂ was 23, which is higher than that of some promising sensors reported in the literature. Finally, humidity measurements showed that PdO/WO₃ sensors displayed low-cross-sensitivity toward water vapor, compared to bare WO₃ sensors. The addition of PdO NPs helps to minimize the effect of ambient humidity on the sensor response