A multi-functional delicate conductive nanostructure of a 3D hierarchical physically linked f-BNNS/clay/PNIPAM hydrogel has been fabricated successfully.

Photocatalysis is considered as one of the most attractive strategies to make full use of sustainable solar light for chemical energy production and pollutant degradation. [1] Abundant active sites, sufficient light absorption ability, and rapid charge separation are the prerequisites for highly efficient photocatalysts. [2][3][4][5][6] Graphitic carbon nitride (g-C 3 N 4 ), as the analogue of graphene, has drawn broad attention on account of its unique optical and electronic properties, good chemical, and thermal stability. However, the over-stacking structure of the bulk g-C 3 N 4 leads to limited active sites and high charge recombination, as well as the insufficient visible-light absorption (bandgap %2.7 eV) severely restrict the photocatalytic performance of the bulk g-C 3 N 4 . [7,8] Two-dimensional (2D) amorphous nanosheets possess exceptional chemical, physical, and electronic properties because they integrate the benefits of both amorphous structure and 2D nature, such as large surface areas, abundant reactive sites, active electronic state, and additional ions/electrons transport paths. [9][10][11][12] 2D ultrathin or amorphous g-C 3 N 4 has been reported to possess superior catalytic activity than the bulk or crystalline counterparts. [13][14][15] However, the long-range disorder in the 2D amorphous nanosheets might suffer from inefficient charge transfer. [16] Heteroatom doping into the g-C 3 N 4 can change the carrier density and provide new electron transport pathways to promote charge separation and transport. [17][18][19][20][21] As one electron-rich atom with similar atom radius to that of nitrogen (N) atom, oxygen (O) atom is considered as an efficient dopant to be able to improve carrier separation and enlarge optical absorption ability. [20][21][22] To date, nevertheless, very few work have concentrated on studying the synergistic effect of the 2D amorphous structure and O-doping on the properties of the g-C 3 N 4 . [23] Therefore, the exploration of a facile and efficient approach to simultaneously achieve the O-doping on 2D amorphous g-C 3 N 4 , and precisely tailor the surface, crystallographic and electronic structure of the g-C 3 N 4 is desirable yet challenging.Supercritical CO 2 (SC CO 2 ), possessing both gas and liquid properties, that is low viscosity, high diffusion, low surface tension, and adjustable solvent characteristics, displays promising talent in 2D nanomaterials design and manufacture. [24,25] In our previous work, SC CO 2 can not only successfully exfoliate various layered materials into 2D nanosheets, [26,27] also achieve phase transformation, [28] heteroatom doping, [29] lateral and vertical heterostructure construction, [30][31][32][33] as well as 2D amorphous materials fabrication. [34][35][36] In this context, 2D O-doped amorphous g-C 3 N 4 nanosheets tailored by SC CO 2 have been first achieved in this work. Impressively, the introduction of SC CO 2 not only led to 2D amorphous structure but also created heteroatom O-doping in the C 3 N 4 skeleton, which caused intr...

Two-dimensional (2D) metal-free ferromagnetic materials are ideal candidates to fabricate next-generation memory and logic devices, but optimization of their ferromagnetism at atomic-scale remains challenging. Theoretically, optimization of ferromagnetism could be achieved by inducing long-range magnetic sequence, which requires short-range exchange interactions. In this work, we propose a strategy to enhance the ferromagnetism of 2D graphite carbon nitride (g-C3N4), which is facilitating the short-range exchange interaction by introducing in-planar boron bridges. As expected, the ferromagnetism of g-C3N4 was significantly enhanced after the introduction of boron bridges, consistent with theoretical calculations. Overall, boosting ferromagnetism of 2D materials by introducing bridging groups is emphasized, which could be applied to manipulate the magnetism of other materials.

Photocatalytic reduction of CO2 into high value‐added fuels paves a new avenue for alleviating the energy crisis and green‐house effect, yet it is still challenging to achieve a highly active photocatalyst with high selectivity. Herein, for the first time, a facile structural engineering strategy is developed to construct tunable frustrated Lewis pairs (FLPs) on 2D amorphous graphitic carbon nitride (C3N4) via the introduction of boric acid with the assistance of supercritical CO2, wherein the FLPs are composed of B(OH)2 groups (Lewis acid sites) and adjacent NHx (Lewis base sites). Ideally, the synergetic effects of the FLPs on the 2D amorphous C3N4 can help to efficiently adsorb, activate, and reduce CO2 to CH4 with enhanced selectivity of ≈96.0%.

Abstract2D graphene with high quality holds great promise in improving the performance of the hydrogels owing to its exceptional electronic, thermal, and mechanical properties. However, the structure defects existed in graphene restrict its further applications. Herein, a simple and green method of fabricating defect‐free graphene nanosheets with the assistance of supercritical carbon dioxide (SC CO2) is designed. The graphene nanosheets directly assemble with acrylic acid monomer and clay, and a flexible semitransparent hydrogel is fabricated. Benefiting from the excellent properties of the defect‐free graphene, the hydrogel exhibits the high mechanical performance, superfast self‐healing capability, excellent conductivity, and super photothermal conversion efficiency. According to the advantages above, the graphene/poly(acrylic acid)/clay hydrogels can be used for intelligent sensors for disease diagnosis, artificial electronic skin, and military stealth materials in the near future.