Scalable Preparation of High-Quality Microwave-Assisted Reduced Graphene Oxide via Spatial Configuration Engineering

The non-uniform heating phenomenon in microwave-assisted synthesis of carbon materials has persistently posed a core challenge restricting the realization of industrial-scale applications for microwave technology. Here, an innovative microwave reduction strategy based on spatial configuration engineering is proposed, solving the problem of uneven product quality in the scale-up preparation of microwave-assisted reduced graphene oxide (m-rGO). The corona-discharge-free and fully exposed irradiation areas jointly determine the stability of batch reduction and quality of m-rGO. The quality of the m-rGO is significantly improved by preferential optimization of the process parameters, achieving an I_D/I_G ratio as low as 0.12 and an excellent electrical conductivity of 13486 S m⁻¹, with a yield of ≈70 g per batch. Due to its high conductivity, lightweight, graphene-based materials have emerged as promising candidates in absorption-dominated electromagnetic interference (EMI) shielding fields. A microwave-assisted reduced graphene oxide/polyurethane (m-rGO/PU) film is prepared with a thickness of 90 µm, exhibiting outstanding EMI SE of up to 40 dB in the X-band. This study provides a strategy for mitigating the quality variability associated with microwave heating technology in the scale-up preparation of various advanced carbon materials, facilitating the industrial application of microwave technology.