reported as a new effi cient Fenton-like catalyst for yielding oxidative hydroxyl radicals (HO•) to degrade organic contaminants. [ 5 ] Other applications are rarely reported in the literature. In any case, it is commonly accepted that the performances are closely related with morphology, structure, specifi c area, and chemical stability of FeOCl nanomaterials, which strongly depends on the preparation strategies and experimental conditions. [ 6 ] For decades, however, almost all the reported FeOCl materials were obtained by one exclusive strategy, the chemical vapor transport (CVT), which utilizes FeCl 3 and Fe 2 O 3 mixed powders as precursor and requires a heating procedure at a temperature of 380 °C over days. [ 5,7 ] The CVT strategy is extremely time consuming and asobtained FeOCl materials possess single morphology of nanoplate with micrometer dimensions. Also, the fi nite experimental parameters make it diffi cult to effectively modulate the microstructure, morphology and composition, which limits its practical applications in fi elds of catalysis, energy storage, and conducting materials. Recently, we developed a new technique, laser ablation in liquid solution (LAL), to facilely synthesize the crystalline FeOCl nanosheets at ambient conditions. By laser ablating Au foil in surrounding FeCl 3 solutions for minutes, spherical Au nanoparticles (NPs) decorated FeOCl nanosheets could be synthesized in a one-pot procedure. Technical characterizations illustrate that the crystalline nanosheets possess (010) preferred orientations with microsized dimensions in the plane and tens of nanometers in thickness. The Au/FeOCl nanocomposites own good thermal stability and surface of which adsorbs abundant H 2 O molecularly and oxygen species chemically. The fabrication route is simple and much more effi cient compared to the traditional CVT method. Furthermore, the crystalline size and proportion of Au or FeOCl in the nanocomposites could be effectively modulated by simply changing FeCl 3 concentrations. We proposed that the localized liquid region, formed around the interface between LAL-induced plasma plume and surrounding liquid, provides the hydrolysis reaction platform for the formation of FeOCl nanosheets.

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Resistance-type metal-oxide semiconductor gas sensors with high sensitivity and low detection limit have been explored for practical applications. They require both sensing films with high sensitivity to target gases and an appropriate structure of the electrode-equipped substrate to support the sensing films, which is still challenging. In this paper, a new gas sensor of metal-oxide porous array films on a micro-gap electrode pair is designed and implemented by taking ZnO as a model material. First, a micro-gap electrode pair was constructed by sputtering deposition on a filament template, which was used as the sensor's supporting substrate. Then, the sensing film, made up of ZnO porous periodic arrays, was in situ synthesized onto the supporting substrate by a solution-dipping colloidal lithography strategy. The results demonstrated the validity of the strategy, and the as-designed sensor shows a small device-resistance, an enhanced sensing performance with high resolution and an ultralow detection limit. This work provides an alternative method to promote the practical application of resistance-type gas sensors.