Developing an ultimate electromagnetic (EM)-absorbing material that can not only dissipate EM energy but also convert the generated heat into electricity is highly desired but remains a significant challenge. Here, we report a hybrid Sn@C composite with a biological cell-like splitting ability to address this challenge. The composite consisting of Sn nanoparticles embedded within porous carbon would split under a cycled annealing treatment, leading to more dispersed nanoparticles with an ultrasmall size. Benefiting from an electron-transmitting but a phonon-blocking structure created by the splitting behavior, an EM wave-electricity device constructed by the optimum Sn@C composite could achieve an efficiency of EM to heat at widely used frequency region and a maximum thermoelectric figure of merit of 0.62 at 473 K, as well as a constant output voltage and power under the condition of microwave radiation. This work provides a promising solution for solving EM interference with self-powered EM devices.

Harvesting largely ignored and wasted electromagnetic (EM) energy released by electronic devices and converting it into direct current (DC) electricity is an attractive strategy not only to reduce EM pollution but also address the ever-increasing energy crisis. Here we report the synthesis of nanoparticle-templated graphene with monodisperse and staggered circular nanopores enabling an EM–heat–DC conversion pathway. We experimentally and theoretically demonstrate that this staggered nanoporous structure alters graphene’s electronic and phononic properties by synergistically manipulating its intralayer nanostructures and interlayer interactions. The staggered circular nanoporous graphene exhibits an anomalous combination of properties, which lead to an efficient absorption and conversion of EM waves into heat and in turn an output of DC electricity through the thermoelectric effect. Overall, our results advance the fundamental understanding of the structure–property relationships of ordered nanoporous graphene, providing an effective strategy to reduce EM pollution and generate electric energy.

Two-dimensional (2D) superlattices, formed by stacking sublattices of 2D materials, have emerged as a powerful platform for tailoring and enhancing material properties beyond their intrinsic characteristics. However, conventional synthesis methods are limited to pristine 2D material sublattices, posing a significant practical challenge when it comes to stacking chemically modified sublattices. Here we report a chemical synthesis method that overcomes this challenge by creating a unique 2D graphene superlattice, stacking graphene sublattices with monodisperse, nanometer-sized, square-shaped pores and strategically doped elements at the pore edges. The resulting graphene superlattice exhibits remarkable correlations between quantum phases at both the electron and phonon levels, leading to diverse functionalities, such as electromagnetic shielding, energy harvesting, optoelectronics, and thermoelectrics. Overall, our findings not only provide chemical design principles for synthesizing and understanding functional 2D superlattices but also expand their enhanced functionality and extensive application potential compared to their pristine counterparts.

Lamellar membranes fabricated through the layer-by-layer stacking of two-dimensional nanosheets hold great promise in the field of nanofiltration (NF) owing to the existence of abundant nanochannels that function as excellent nanofilters. However, the NF performance of these lamellar membranes is severely limited by the irregularity of the nanochannels and the stacking defects of the nanosheets. To address this issue, a facile approach was proposed in this study, which involved the modification of lamellar MXene membranes intercalated with Ag nanoparticles (Ag@MXene) using tea polyphenols (TPs). Upon the TP modification, the initial wrinkles present in the MXene nanosheets were flattened, which effectively reduced the stacking defects and increased the regularity of the nanochannels. Consequently, the water permeability of the TP-modified Ag@MXene (Ag@MXene-TP) membrane significantly increased up to 137.7 Lm−2 h−1·bar−1, a value that was three times the permeability of the pristine MXene membrane. Importantly, the Ag@MXene-TP membrane maintained a high dye rejection rate, with values of 95.85% for Rhodamine B and 97.30% for Congo Red. Molecular dynamics simulations further elucidated the underlying mechanism for the water permeability enhancement. It was found that the adsorption of TPs on the MXene surface prevented the aggregation of MXene nanosheets by shielding the electrostatic attraction between the MXene nanosheets and the Ag nanoparticles. In addition, the enhanced regularity of the nanochannels was also found to cause largely reduced water transport resistance. This pre-modification strategy of MXene nanosheets with TPs provides a new way to build MXene-based nanochannels with improved regularity for high-performance NF membranes.