The energy and environmental crises have forced us to search for a new green energy source and develop energy storage and environmental restoration technologies. Fabrication of carbon functional materials derived from coal has attracted increasing attention in the energy storage and gas adsorption fields. In this study, an N, O-co-doped porous carbon/carbon nanotube composite was prepared by functionalizing coal-based porous carbon with carbon nanotubes (CNTs) and ionic liquid via annealing. The resulting material not only inherited the morphology of CNTs and porous carbon, but also developed a three dimensional (3D) hierarchical porous structure with numerous heteroatom groups. The N, O co-doped porous carbon/CNT composite (N, O-PC-CNTs) showed a surface area of 2164 m² g⁻¹, and a high level of N/O dopants (8.0 and 3.0 at%, respectively). Benefiting from such merits, N, O-PC-CNTs exhibited a rather high specific capacitance of 287 F g⁻¹ at a current density of 0.2 A g⁻¹ and a high rate capability (70% and 64% capacitance retention at 10 and 50 A g⁻¹, respectively) in a three electrode system. Furthermore, an N, O-PC-CNT symmetrical supercapacitor showed a high cycling stability with 95% capacitance retention after 20 000 cycles at 20 A g⁻¹ and an energy density of 4.5 W h kg⁻¹ at a power density of 12.5 kW kg⁻¹ in 6 mol L⁻¹ KOH electrolyte. As a CO₂ adsorbent, N, O-PC-CNTs exhibited a high CO₂ uptake of 5.7 and 3.7 mmol g⁻¹ at 1 bar at 273 and 298 K, respectively. Moreover, N, O-PC-CNTs showed cycling stability with 94% retention of the initial CO₂ adsorption capacity at 298 K over 10 cycles. This report introduces a strategy to design a coal based porous carbon composite for use in efficient supercapacitor electrodes and CO₂ adsorbents.

Computing in memory (CIM) breaks the conventional von Neumann bottleneck through in situ processing. Monolithic integration of digital and analog CIM hardware, ensuring both high precision and energy efficiency, provides a sustainable paradigm for increasingly sophisticated artificial intelligence (AI) applications but remains challenging. Here, we propose a complementary metal-oxide semiconductor–compatible ferroelectric hybrid CIM platform that consists of Boolean logic and triggers for digital processing and multistage cell arrays for analog computation. The basic ferroelectric-gated units are assembled with solution-processable two-dimensional (2D) molybdenum disulfide atomic-thin channels at a wafer-scale yield of 96.36%, delivering high on/off ratios (>10 ⁷ ), high endurance (>10 ¹² ), long retention time (>10 years), and ultralow cycle-to-cycle/device-to-device variations (~0.3%/~0.5%). Last, we customize a highly compact 2D hybrid CIM system for dynamic tracking, achieving a high accuracy of 99.8% and a 263-fold improvement in power efficiency compared to graphics processing units. These results demonstrate the potential of 2D fully ferroelectric-gated hybrid hardware for developing versatile CIM blocks for AI tasks.

Efficient electrodes with impressive storage capability and fast ion transfer rate are urgently needed to meet the demand for higher energy/power densities and longer life cycles and large rate powering devices. Through a simple freeze-drying and annealing process, nitrogen-containing porous carbon materials with a hierarchical porous structure and enlarged lattice spacing between graphene layers are synthesized. Benefiting from an improvement in the electrochemical activity, porosity, conductive network and mechanical stability, the porous carbon used as anodes for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) exhibits an excellent storage capability, rate performance, and cyclability. Apple carbon exhibits a high capacity of 1050 mA h g⁻¹, and celery carbon shows the reversible capacities of 990 mA h g⁻¹ at 0.1 A g⁻¹ after the 200th cycle as LIBs anodes. For SIBs, a high capacity of 438 mA h g⁻¹ is obtained after 200 cycles for apple carbon and 451 mA h g⁻¹ for celery carbon. It is noteworthy that celery carbon shows a capacity retention of 94% between the 50th to 200th cycling. Further analysis on the structure characterization and charging curves reveal that celery carbon has a high N content, dilated intergraphene spacing, and an intrinsically hierarchical porous structure, which are capable of reversibly accumulating sodium ions through surface adsorption and sodium intercalation. Also, the electrochemical impedance spectroscopy (EIS) reveals that celery carbon has a low charge-transfer resistance, the enhanced cyclability and rate performance might be attributed to convenient ion diffusion in the electrode.

Biochar-based carbonaceous adsorbents are gaining interest due to their high availability, ease of modification, and low cost; however, they show limited adsorption of CO₂ in flue gas due to common textural properties. In this study, TEPA-modified biochar was used to prepare a solid amine adsorbent for the efficient capture of CO₂ in flue gas. First, the porous biochar was prepared with FeCl₃, Mg(NO₃)₂, and H₂O (g) as activators and walnut shells as carbon sources. Next, the biochar was modified with TEPA to obtain a solid amine adsorbent. Porous texture properties and sample surface functional groups were characterized, and we measured the adsorption CO₂ of the amine-modified biochar in a breakthrough adsorption device. Results showed that biochar has a large specific surface area (744.38 m² g⁻¹), a total pore volume of 1.41 cm³ g⁻¹, and a high mesoporous volume ratio (82.7%). The high pore volume provided a more efficient support space for loading tetraethylenepentamine (TEPA). The adsorbent had an excellent CO₂ adsorption capacity, corresponding to 2.82 mmol g⁻¹, which increased to 3.31 mmol g⁻¹ and kept water resistance at 10% H₂O (g) simulated flue gas (SFG). The FTIR analysis showed that H₂O (g) inhibited urea production after cyclic adsorption. Therefore, solid amine adsorbent created by amine-modified biochar has potential advantages in its application for capturing CO₂ in SFG.

In this paper, porous zinc oxide (ZnO) nanosheets were successfully prepared by a simple low-temperature hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) tests showed that the synthesized product was ZnO with porous sheet structure. The diameter of porous nanosheets was about 100 nm and the thickness was about 8 nm. As a photocatalyst, the degradation efficiencies of porous ZnO nanosheets for methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB) were 97.5%, 99% and 96.8%, respectively. In addition, the degradation efficiency of ZnO for mixed dyes (Mo, MB and RhB) was satisfactory, reaching 97.7%. The photocatalytic stability of MB was further tested and remained at 99% after 20 cycles. In the experiment, ZnO/FTO (fluorine-doped tin oxide) composites were prepared by using ZnO as the conductive layer. Titanium dioxide (TiO₂) was deposited on the surface of ZnO/FTO by electrodeposition, so as to obtain a TiO₂/ZnO/FTO composite. By studying the electrochromic properties of this composite, it was found that the TiO₂/ZnO/FTO composite shows a large light modulation range (55% at 1000 nm) and excellent cycle stability (96.6% at 200 cycles). The main reason for the excellent electrochromic properties may be the synergistic effect between the porous structure and the polymetallic oxides. This study is helpful to improve the photocatalytic efficiency and cycling stability of metal oxides, improve the transmittance of thin films and provide a new strategy for the preparation of ZnO composite materials with excellent photocatalytic and electrochromic properties.