Two-dimensional material inspired tremendous research interest by its unique structure and specific property different from bulk material, which could benefit various applications such as optics, electronics, and chemistry. However, most documented processes for 2D materials are complicated with a lengthy process. We introduced the cellulose nanofiber (CNF) extracted from agricultural waste rice straws, which inherently possesses many functional groups, e.g., hydroxyl group, and carboxylate group, making it a terrific template method candidate. Besides, aerogel composed of cellulose nanofiber provides many surface and layered structures that facilitate the adhesion of titanium isopropoxide to form a uniform coating layer, which hydrolyzed to TiO_2. The cellulose nanofiber serves as a template and could be removed entirely in an easy thermal process by thermogravimetric analysis; meanwhile, we can transform the original amorphous TiO₂ nanosheet into an anatase phase which is flavored in the photocatalyst field. Atomic force microscopy (AFM) results spotted a stacked ultrathin TiO₂ nanosheet with a thickness of less than 5 nm for each layer, and the lateral size could reach micron size. For the RhB dye degradation test, TiO₂ nanosheets could decompose the 10 ppm RhB solution within 30 mins with a reaction rate of 0.065 min^-1. In conclusion, we combine the CNF template and hydrolysis process, proposing a simple 2D TiO₂ nanosheets

This study realized the large-scale piezo-catalytic RhB dye degradation by forming a catalytic filter of 2H phase MoS₂ and carbon cloth. Over 2.5 liters of the organic pollutant can be fully decomposed through the application of a water pumping system. The results obtained indicate that 2H MoS₂ NFs were highly reusable and have excellent potential for the application in industrial wastewater treatment. Furthermore, this study theoretically and experimentally investigates the piezocatalytic and adsorption effects of different phases of polymorphic MoS₂ NFs. By adjusting the electrostatic surface charge of these NFs and the RhB solution, different crystalline phases of MoS₂ NFs would result in either adsorption or piezo-catalytic effects toward the organic dye. The results evident that the cationic dye is adsorbed on the surfaces of the 1T MoS₂ NFs; however, the few-layer 2H MoS₂ NFs generate a considerable quantity of hydroxyl species for degrading RhB molecules through the mechanical-force-induced piezo-potential.

Figure 1