Microfluidic Oxidation of Graphite in Two Minutes with Capability of Real‐Time Monitoring

Abstract

Graphite oxide and its exfoliated counterpart, graphene oxide, are important precursors for the large‐scale production of graphene‐based materials and many relevant applications. The current batch‐style preparation of graphite oxide suffers from safety concern, long reaction time, and nonuniform product quality, due to the large volume of reactors and slow energy exchange. Reaction in microchannels can largely enhance the oxidization efficiency of graphite due to the enhanced mass transfer and extremely quick energy exchange, by which the controllable oxidization of graphite is achieved in ≈2 min. Comprehensive characterizations show that the graphene oxide obtained through the microfluidic strategy has features like those prepared in laboratory beakers and industrial reactors, yet with the higher oxidization degree and more epoxy groups. More importantly, the microfluidic preparation allows for on‐line monitoring of the oxidization by Raman spectroscopy, ready for the dynamical control of reaction condition and product quality. The capability of continuous preparation is also demonstrated by showing the assembly of fibers and reduction of graphene oxide in microfluidic channels, and the applicability of graphene oxide prepared from the microfluidic strategy for thermally and electrically conductive films.

Synchronous Redox Reactions in Copper Oxalate Enable High-Capacity Anode for Proton Battery

“…After complete discharge, the O–CO bond to C–O ratio significantly decreased compared with the initial state (Figure S18d). ,− …”

Towards Automated Microfluidic‐based Platforms: Optimizing Hydrogenation Efficiency of Nitrobenzene through π–π Interactions in Pd Nanoparticles on Covalent Organic Frameworks

“…The more precise control and manipulation of reactor size with which it can run, the more likely the fundamental principle can be recognized, especially in the nano‐ and micro‐scale [16] . Microfluidics has grown in stature as a continuous‐flow method with advantages of precision, ease‐to‐use, and free from environmental impact [17, 18] . Similar to nature's way of capillary action in a narrow space, microfluidics has shown the distinctive behavior of confined microchannel size and an extremely high surface‐to‐volume ratio, contributing to the enhancement of mass and heat transfer.…”

“…[16] Microfluidics has grown in stature as a continuous-flow method with advantages of precision, ease-to-use, and free from environmental impact. [17,18] Similar to nature's way of capillary action in a narrow space, microfluidics has shown the distinctive behavior of confined microchannel size and an extremely high surface-to-volume ratio, contributing to the enhancement of mass and heat transfer. The integration of microfluidics with automated system has, therefore, enabled tremendous opportunities for better understanding and leveraging catalytic nanotechnology.…”

Photo‐Mediated Cascade Growth of Ag Nanocrystals in Flow Reactors for High‐Performance Flexible Transparent Electrodes

“…Flow reactor, owing to its enhanced mass/energy transfer efficiency, is more favorable for extensive and exquisite production, which has been successfully applied in pharmaceutics and fine chemistry. [ 18 ] From the viewpoint of safety and efficiently sustainable chemistry, subtle flow reactors minimize risks involving hazardous reactants because of their small volumes, and effective mixing and transport of reagents. [ 19 ] Fascinatingly, the photo‐mediated method combining flow reactors, which simplifies the synthetic process and enhances reaction efficiency, not only can be extended to the preparation of other metal or alloy nanocrystals but also allows for one‐piece integration into various applications, especially high‐performance and cost‐effective flexible optoelectronics.…”