Fabrication of cellulose nanocrystal supported stable Fe(0) nanoparticles: a sustainable catalyst for dye reduction, organic conversion and chemo-magnetic propulsion

This article reports a single-step "green protocol" for the environmentally friendly synthesis of zerovalent iron (ZVI) nanoparticles supported on cellulose nanocrystals (CNCs) fabricated from bamboo pulp. The high content of available hydroxyl groups on the CNC surfaces is utilized as an anchor point for the simultaneous reduction and stabilization of the CNC-supported ZVIs. In this approach, Na-CNCs act as corrosion inhibitors and enhance the catalytic activity of ZVI as it retains a zero state even after 5 days of exposure to air. Furthermore, CNC-supported ZVIs are found with narrow size distribution along with improved dispersion stability in water. The CNC-supported ZVIs successfully degraded the methylene blue, making it a potentially active and nontoxic biocatalyst for wastewater remediation. Moreover, it was also found to be active toward the hydrogenation of 4-nitrophenol into 4-aminophenol. Furthermore, we observed the autonomous motion of CNC-supported ZVIs in the presence of peroxide fuel whose trajectories were found to be externally controlled under both magnetic fields and pH gradients. Interestingly, we can remotely tune the speed and controlled trajectory of CNC-supported ZVIs, making these motors a potential candidate for the next-generation nanomachines for sensors, imaging and drug delivery applications.