One-Step, Solventless, and Scalable Mechanosynthesis of WO₃·2H₂O Ultrathin Narrow Nanosheets with Superior UV–Vis-Light-Driven Photocatalytic Activity

Abstract

Environmentally benign, high-yield, cost-efficient, and facile fabrication of ultrathin two-dimensional (2D) nanomaterials has been a bottleneck restricting their massive and extensive applications. In this work, a one-step, solvent-free, and easily scalable approach for the preparation of WO3·2H2O ultrathin narrow nanosheets has been proposed for the first time, which is based on solid-state mechanochemical reaction between sodium tungstate dihydrate (Na2WO4·2H2O) and oxalate dihydrate (H2C2O4·2H2O) at ambient temperature. The resulting WO3·2H2O presents uniform rectangular nanosheets with a typical length of 50–80 nm, a width of about 10 nm, and a thickness of 5.67 nm. Phase evolution in the synthetic process of WO3·2H2O ultrathin narrow nanosheets was investigated by X-ray diffractometry. Their formation mechanism was also rationalized on the basis of in situ precipitation and preferential growth of ionized WO4 2– on the surface of mechanically exfoliated oxalate nanosheets. The WO3·2H2O ultrathin narrow nanosheets exhibit excellent adsorptive and UV-to-vis-light-driven photocatalytic properties with adequate recyclability in the removal of Rhodamine B (RhB) from aqueous solution, and also show promise for potential applications in photoelectronic devices, gas sensors, supercapacitors, lithium-ion batteries, and other environmental remediation.

Oxygen-Deficient Tungsten Oxide (WOx) Nanobelts with pH-Sensitive Degradation for Enhanced Sonodynamic Therapy of Cancer

“…WO x nanobelts (NBs) were successfully synthesized via a facile solid-state mechanochemical method. 26 Briefly, Na 2 WO 4 and H 2 C 2 O 4 were evenly mixed and milled with a planetary ballmill at room temperature, and then, the resulting chartreuse powder was purified with centrifugation to remove the large aggregates (Figure 1A). An X-ray diffraction (XRD) pattern verified the high purity of dihydrated monoclinic WO 3 (JPCDS 18-1420) (Figure 1B).…”

In situ monitoring of mechanochemical synthesis of calcium urea phosphate fertilizer cocrystal reveals highly effective water-based autocatalysis

“…Indeed, previous studies have noted that a liquid phase released from a hydrated starting material can enhance the formation of hydrogen-bonded cocrystals or coordination polymers. [20][21][22][23][24][25] However, there has not yet been a real-time, quantitative investigation of how a product formed in a chemical reaction, which involves the rearrangement of covalent bonds, could exhibit autocatalytic behaviour in mechanochemistry.…”

Ag/VO2/Ag sandwich nylon film for smart thermal management and thermo-responsive electrical conductivity

“…In the synthesis system of VO 2 , the oxalic acid tends to form sheet shape and serves as a template for VO x growth. Upon crystal growth, an oriental attachment is a simultaneous process, which has a tendency to minimize the most energetically unstable surface facets by fast and preferential growth perpendicular to the correspondent facet [34]. Thus in the first step, short and narrow nanowires with cross section of rectangular shape were formed.…”