Room-temperature gas sensor based on in situ grown, etched and W-doped ZnO nanotubes functionalized with Pt nanoparticles for the detection of low-concentration H2S

Natural light driven photovoltaic-electrolysis water splitting with 12.7% solar-to-hydrogen conversion efficiency using a two-electrode system grown with metal foam

Semiconductor-based photocatalyst materials played an important role in the degradation of organic compounds in recent years. Photocatalysis is a simple, cost-effective, and environmentally friendly process for degrading organic compounds. In this work, vanadium pentoxide (V2O5) and V2O5/RGO (reduced graphene oxide) composite were synthesized by a hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Raman spectroscopy, and UV-Vis spectroscopic analysis, etc. Raman analysis shows the occurrence of RGO characteristic peaks in the composite and different vibrational modes of V2O5. The band gap of flake-shaped V2O5 is reduced and its light absorption capacity is enhanced by making its composite with RGO. The photocatalytic degradation of methylene blue (MB) was studied using both V2O5 and V2O5/RGO composite photocatalyst materials. The V2O5/RGO composite exhibits a superior photocatalytic performance to V2O5. Both catalyst and light play an important role in the degradation process.

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Enhanced Photocatalytic Degradation Activity Using the V2O5/RGO Composite

In recent decades, chemiresistive gas sensors (CGS) have been widely studied due to their unique advantages of expedient miniaturization, simple fabrication, easy operation, and low cost. As one ubiquitous interference factor, humidity dramatically affects the performance of CGS, which has been neglected for a long time. With the rapid development of technologies based on gas sensors, including the internet of things (IoT), healthcare, environment monitoring, and food quality assessing, the humidity interference on gas sensors has been attracting increasing attention. Inspiringly, various anti-humidity strategies have been proposed to alleviate the humidity interference in this field; however, comprehensive summaries of these strategies are rarely reported. Therefore, this review aims to summarize the latest research advances on humidity-independent CGS. First, we discussed the humidity interference mechanism on gas sensors. Then, the anti-humidity strategies mainly including surface engineering, physical isolation, working parameters modulation, humidity compensation, and developing novel gas-sensing materials were successively introduced in detail. Finally, challenges and perspectives of improving the humidity tolerance of gas sensors were proposed for future research.

/pdf/recent-progress-on-anti-humidity-strategies-of-2km8muny.pdf

Recent Progress on Anti-Humidity Strategies of Chemiresistive Gas Sensors

Mechanical energy-induced CO2 reduction is a promising strategy for reducing greenhouse gas emissions and simultaneously harvesting mechanical energy. Unfortunately, the low energy conversion efficiency is still an open challenge. Here, multiple-pulse, flow-type triboelectric plasma with dual functions of harvesting mechanical energy and driving chemical reactions is introduced to efficiently reduce CO2. CO selectivity of 92.4% is achieved under normal temperature and pressure, and the CO and O2 evolution rates reach 12.4 and 6.7 µmol h−1, respectively. The maximum energy conversion efficiencies of 2.3% from mechanical to chemical energy and 31.9% from electrical to chemical energy are reached. The low average electron energy in triboelectric plasma and vibrational excitation dissociation of CO2 with low barrier is revealed by optical emission spectra and plasma simulations, which enable the high energy conversion efficiency. The approach of triboelectric plasma reduction reported here provides a promising strategy for efficient utilization of renewable and dispersed mechanical energy. 

Triboelectric Plasma CO <sub>2</sub> Reduction Reaching a Mechanical Energy Conversion Efficiency of 2.3%

Fabrication of a humidity-resistant formaldehyde gas sensor through layering a molecular sieve on 3D ordered macroporous SnO2 decorated with Au nanoparticles

The simultaneous activation of surface lattice oxygen and dioxygen is key to transition metal oxide-based catalytic CO oxidation systems. However, the reaction is difficult at room temperature owing to the high metal–oxygen bond energy. This study presents a triboelectric plasma–transition metal oxide catalytic system driven by a triboelectric nanogenerator, which realizes CO oxidation reaction at room temperature and atmospheric pressure. Among the transition metal oxides evaluated, MnO2 nanostructures exhibited an optimal CO oxidation activity of 0.24 mmol·g–1·h–1 and a low energy consumption converted per mole CO of 6.0 × 103 kJ. For the activation of both surface lattice oxygen and dioxygen, multiple reaction pathways with barriers ranging from 0.37 to 2.43 eV have been revealed by X-ray photoelectron spectroscopy, electron paramagnetic resonance, and density functional theory simulation. These catalytic reaction phenomena have been explained by an extended Mars–van Krevelen mechanism, in which multiple pathways with various barriers were overcome by the electrons in the plasma with a uniform and broad distribution probability. This work provides an efficient strategy for the conversion and utilization of mechanical energy for chemical synthesis. 

Triboelectric Plasma-Catalytic CO Oxidation of MnO<sub>2</sub> Nanostructures Driven by Mechanical Energy at Room Temperature

The self-powered agricultural sensing system with 1.7 km wireless multichannel signal transmission using a pulsed triboelectric nanogenerator of corn husk composite film

أحمد عطية عبد الكريم الزهراني

Papers

Fabrication of a humidity-resistant formaldehyde gas sensor through layering a molecular sieve on 3D ordered macroporous SnO2 decorated with Au nanoparticles

Triboelectric Plasma-Catalytic CO Oxidation of MnO<sub>2</sub> Nanostructures Driven by Mechanical Energy at Room Temperature

Triboelectric Plasma CO <sub>2</sub> Reduction Reaching a Mechanical Energy Conversion Efficiency of 2.3%

The self-powered agricultural sensing system with 1.7 km wireless multichannel signal transmission using a pulsed triboelectric nanogenerator of corn husk composite film