Two-dimensional (2D) BiVO 4 nanosheets (NSs), featuring distinctive chemical properties and dangling-bond-rich surfaces, are promising for developing high-performance gas sensors. However, the previously reported 2D BiVO 4 NSs-based devices suffer from a low responsivity and poor selectivity. In this work, we introduce RuO 2 nanoparticles to boost the gas sensing properties of 2D BiVO 4 NSs-based sensor. Intriguingly, the RuO 2 -decoration changes the selectivity of the corresponding gas sensor from acetone to xylene. Compared to the pristine BiVO 4 sensor, the RuO 2 -BiVO 4 sensor displays a reduced optimal operating temperature of 260℃ and exhibits a response of 19.0–5 ppm xylene, reaching a five-fold enhancement. Simultaneously, the RuO 2 -BiVO 4 sensor also exhibits a rapid response and recovery time of 10 and 25 s respectively, as well as robust long-term stability with less than 5 % variation in response after a storage of 60 days. The improvement in sensing performance can be attributed to the RuO 2 -decoration from three aspects: heterojunction construction, surface state modulation and gas oxidation catalysis on the surface. This work not only provides a high-performance xylene sensing material but also provides insightful comprehension regarding the modification effects of RuO 2 .
The controllable synthesis of oxygen evolution reaction (OER) electrocatalyst is an urgent need to advance the development of sustainable energy conversion and storage. However, the OER efficiency in acidic media is seriously hindered by slow reaction kinetics. The traditional acidic OER electrocatalysts are more prone to be oxidized and corroded as results of unstable carrier structures and variable electronic states of active species. Herein, a high-performing biochar aerogel (BA) based electrocatalyst were realistically designed and synthetized via joint utilization of the terrestrial lignin and seaweed polysaccharide as carbon sources. Originating from the induction effect of "egg-box" structure in alginate and the self-template effect of lignosulfonate, the BA decorated with Ru/RuS 2 particles was synthesized triumphantly. The as-synthesized electrocatalyst required a low overpotential of 228 mV to attain 10 mA cm −2 in 0.5 M H 2 SO 4 and exhibited a good stability for over 12,000 s. The good activity was strongly dependent on the assembled unique two-dimensional/three-dimensional (2D/3D) channels in carbon aerogels. Notably, the numerous defective sites at carbon could strongly interact with the Ru/RuS 2 heterojunction for remarkably enhancing the catalytic activity and stability of whole catalytic system in acidic media. This work puts forward a novel and effective strategy towards the enhancement of the acidic OER process by rational regulations of the BA and the coupling effect in micro-interface. Graphical Abstract
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