Polarization Loss Enhancement Induced by Interfacial Contact Regulation Strategy to Develop Nickel Silicate/Reduced Graphene Oxide for Microwave Absorption and Corrosion Resistance

ABSTRACT Interface polarization enhancement and impedance matching optimization are the keys to improving the comprehensive performance of microwave absorbing materials (MAMs). Herein, a green synthesis strategy integrating sacrificial template self‐etching, hydrothermal reaction, and annealing treatment is proposed to successfully fabricate urchin‐like nickel silicate (Ni 3 Si 2 O 5 (OH) 4 )/highly reduced graphene oxide (HRGO) hollow nanocomposites (HNCs). By precisely controlling the addition of graphene oxide (GO), the content of HRGO in the Ni 3 Si 2 O 5 (OH) 4 /HRGO HNCs can be effectively regulated, which significantly boosts the contact interface and polarization loss. And the modulation of heat treatment synchronously improves the reduction degree of HRGO and the crystallinity of Ni 3 Si 2 O 5 (OH) 4 , thereby further optimizing the electromagnetic (EM) and microwave absorption performances (MAPs). This synergistic strategy of multi‐scale structural design and component regulation enables the designed urchin‐like Ni 3 Si 2 O 5 (OH) 4 /HRGO HNCs to possess low density, strong interfacial polarization loss, excellent impedance matching, and corrosion resistance. Experimental results demonstrate that the optimized Ni 3 Si 2 O 5 (OH) 4 /HRGO HNCs achieve an effective absorption bandwidth of 7.00 GHz at a thickness of 2.47 mm and a minimum reflection loss of −52.77 dB at 2.03 mm, exhibiting outstanding MAPs. For that reason, this research provides a simple interfacial area regulation strategy to enhance polarization loss for developing lightweight, efficient, corrosion‐resistant, and environmentally friendly hollow‐structured MAMs.