In the endeavor to develop 3D-architected sophisticated hierarchical structures, the synergy between in-plane and out-of-plane interactions at interfaces offers new functionalities. This interplay, governed by van der Waals (vdW) interfacial nanoarchitectonics, facilitates the design of efficient thermally conductive pathways. This work delves into the kinetics underlying a dual-templating strategy, seamlessly integrating 2D-graphene sheets with 1D-cellulose chains at heterointerfaces, thereby transforming into 3D-shaped, 3D-continuously anisotropic structures, termed as (3D²GC) architecture. Hereby, we have designed and fabricated an anisotropic graphene cellulose scaffold (GCS) employing a nickel template. The as-grown GCS replicates the 3D-shaped and configuration of the template. The 3D-continuously interconnected fibrous-porous network of the GCS, combined with its anisotropic thermal properties (λ_axial/λ_radial), not only promising for advanced thermal technologies but also offer advantages in cost-effectiveness and eco-effectiveness.

Single-atom alloys (SAAs) have gained significant attention due to their remarkable atomic utilization efficiency, interactions between single atoms (SAs) and metal supports, and free-atom-like electronic structure of dopant elements. In this work, we observed the formation of SAs in pre-deposited metal particles by a two-step thermal evaporation technique, thereby establishing the first instance of discovering SAAs by thermal evaporation. The discovery of SAAs by thermal evaporation extends the range of SAAs preparation methods to include this traditional synthetic technique, which offers convenience, cost-efficiency, and universality. The formation mechanism of SAAs prepared using this technique was elucidated by density functional theory calculations. It was demonstrated that thermal evaporation can be utilized to prepare SAAs with multiple SAs, further highlighting its universal applicability.

A facile way to grow few-layer graphene on high-entropy alloy sheets is presented in this work. We systematically investigate the growth mechanism of graphene using the unique properties of FeCoNiCu_0.25 high-entropy alloys. The intrinsic-trap-regulating growth mechanism derives from the synergistic effect of the multi-metal atoms and sluggish diffusion of high-entropy alloy. As a result, as-obtained few-layer of graphene has the characteristics of wide coverage, large size, good continuity, and high crystallinity with less amorphous carbon and extra wrinkles. Factors such as the Cu content, annealing time, growth temperature, growth time, carbon source flow rate, hydrogen flow rate and heat treatment method play a key role in the growth of high-quality graphene, and the best growth parameters have been explored. Besides, increasing alloy entropy is found to be responsible for the formation of high-quality graphene.

The development of efficient and stable electrocatalysts with earth-abundant elements for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in the same electrolyte is incontrovertibly vital in water electrolysis. However, their large-scale fabrication remains a great challenge. Here, we report a self-supported electrocatalyst in the form of Fe-doped Ni₃S₂ nanoparticles in-situ grown on three-dimensional (3D) conductive Fe-Ni alloy foam (Fe-Ni₃S₂/AF) by surface-assisted chemical vapor transport (SACVT) method. Homogeneous growth environment and scalability of SACVT method allow Fe-Ni₃S₂ nanoparticles uniformly growing on AF in large-scale. Fe-Ni₃S₂/AF exhibits high activity and durability when act as HER catalyst and OER precatalyst in alkaline media. The HER and OER overpotential at 10 mA/cm² is considerably small, only 75 and 267 mV, respectively. Moreover, the electrolyzer assembled by Fe-Ni₃S₂/AF for overall water splitting exhibits a low cell voltage and high durability in long-term test. Based on experiments and theoretical calculation, the significantly enhanced activity could be originated from the incorporation of Fe, which contributed to increase the electrochemical active surface area, enhance electrical conductivity, optimize the hydrogen and H₂O adsorption energy of Ni₃S₂ (101) surface in HER, and form active bimetallic Ni-Fe(oxy)hydroxide in OER. The excellent durability of self-supported Fe-Ni₃S₂/AF could be benefited from the in-situ growth of Fe-Ni₃S₂ nanoparticles on 3D AF, which could ensure closely mechanical adhesion between active materials and substrate, promote charge transport and increase surface area. This work provides a facile method for large-scale synthesis of electrocatalysts with high activity and long-term durability for efficient water electrolysis in alkaline media.

Traditional ionic liquids are sensitive to humidity but with long response time and nonlinear response. Pure liquid-state ionic liquids are usually hard for dehydration which have ultralong response time for humidity sensing. The immobilization of ionic liquids provide a possible way for high performance humidity sensing. Hydrophobic materials and structures also promised faster response in humidity sensing, because of easier desorption of water. In this work, we prepared flexible humidity sensitive composites based on hydrophobic ionic liquid and polymer. The combination of hydrophobic ionic liquid with hydrophobic polymer realized linear response, high sensitivity with low hysteresis to humidity. By adjusting the ratio of ionic liquid, not only the impedance but also the hydrophobicity of composite could be modulated, which had a significant influence on the humidity sensing performance. The morphology and microstructure of the material also affected its interaction with water molecules. Due to the diverse processing methods of polymer, highly transparent film fabricated by spinning-coating and nanofibrous membrane fabricated by electrospinning could be prepared and exhibited different response time, which could be used for different application scenarios. Especially, the fibrous membrane made with electrospinning method showed an ultrafast response and could distinguish up to 120 Hz humidity change, due to its fibrous structure with high specific surface area. The humidity sensors with ultrafast, linear response and high sensitivity showed potential applications in human respiratory monitoring and flexible non-contact switch. To better show the multifunction of ionic liquid-polymer composite, as a proof of concept, we fabricated an integrated humidity sensitive color change device by utilizing lower ionic liquid content composite for sensing in the humidity sensing module and higher ionic liquid content composite as the electrolyte in the electrochromic module.

Although Fe₃O₄ particles have exhibited excellent microwave absorbing capacity and widely used in practical application due to the synergistic effect of magnetic loss and dielectric loss, their applications are still limited for the required high mass fraction in absorbers. To overcome this problem, the development of Fe₃O₄ materials with low dimensional structures is necessary. In this study, the shape anisotropic Fe₃O₄ nanotubes (NTs) with low mass ratios were applied to realize efficient microwave absorption. The NTs with different aspect ratios were prepared through facile electrospinning followed by two-step thermal treatments and mechanical shearing. The cross-linked nanotubular structure enabled the absorbers to have much higher electrical conductivity, multiple scattering, polarization relaxation and better anti-reflection surface, while the shape anisotropic NTs maintained significant multiple resonances with stronger coercivity. These all were beneficial to microwave absorption with enhanced dielectric loss, magnetic loss and sterling impedance matching. Results showed that the absorber with 33.3 wt.% of short Fe₃O₄ NTs had minimum reflection loss of -58.36 dB at 17.32 GHz with a thickness of 1.27 mm, and had the maximum effective absorbing bandwidth (EAB) of 5.27 GHz when the thickness was 1.53 mm. The absorber with 14.3 wt.% of long Fe₃O₄ NTs presented the widest EAB in certain radar band with attenuated 80.75% X band and 85% Ku band energy bellow -10 dB at the thickness of 2.65 and 1.53 mm, respectively. This study provided an approach for the development of shape anisotropic magnetic absorbing materials, and broadened their practical applications as magnetic absorbers.

"PlantNanOmics" is an emerging topic in agricultural research that explores the potential effect of application of nanomaterials on plant growth. Graphene oxide (GO) has excellent properties due to its basal carbon plane and oxygen-containing functional groups. In the present work, the antimicrobial activity of GO was exploited to extend the vase life and improve the quality of cut roses (cv. Carola). The results revealed that the cut roses cultivated in low doses of GO (0.1 mg/L) had longer vase life, larger diameter, and better water relations. Microbial contaminations at the basal stem end is the most common reason for stem blockage that causes water stress and early wilting of cut flowers. GO was found to act as a germicide, effectively inhibiting the microbial growth at the cut stem end and improving water uptake and water balance of cut roses. Therefore, GO can serve as a promising preservative to increase the ornamental value of cut flowers.

Graphene oxide (GO) is a graphene derivative bearing various oxygen-containing functional groups attached to the basal plane and to the edges of the graphene lattice and hence has a unique structure in which numerous hydrophobic sp² clusters are isolated within the hydrophilic sp³ C–O matrix. In this study, the hydrophilic nature and water-transporting properties of GO were exploited to promote germination and growth of plants. It was found that a low dose of GO significantly promoted the germination of spinach and chive in soil. The oxygen-containing functional groups of GO collected water, and the hydrophobic sp² domains transported water to the seeds to accelerate the germination of plants. The strong interaction between GO and the surfaces of soil grains stabilized GO in the soil and prevented dissipation of GO. In addition, no GO was detected either on the surface or inside the cells of plants; this finding confirmed that GO was not phytotoxic. Therefore, GO may serve as a promising nontoxic additive to increase a plant yield.

Heteroatom doping can open the bandgap and increase the carrier density, thus extending the applications of graphene. Iron chloride (FeCl₃) intercalation has proven to be an efficient method for the heavy doping of graphene. In this study, we prepared continuous chemical vapor deposited graphene (CVD-G) consisting of hexagonal adlayer domains to study the FeCl₃ intercalation. The structure of the FeCl₃-treated CVD-G was easily characterized via atomic force microscopy because of the change in the interlayer distance. FeCl₃ crystals several nanometers thick were integrated with the graphene surface, and FeCl₃ layer flakes were intercalated between the CVD-G adlayers. The G-band position and two-dimensional band shape in the Raman spectra confirmed the intercalation of the FeCl₃ between the graphene layers. The FeCl₃ intercalation increased the electrical conductivity of the CVD-G with a well-maintained transmittance, which could be beneficial for a sensitive photodetector.

Cost-effective hydrogen production via electrolysis of water requires efficient and durable earth-abundant catalysts for the hydrogen evolution reaction (HER) over a wide pH range. Herein, we report sponge-like nickel phosphide– carbon nanotube (Ni_xP/CNT) hybrid electrodes that were prepared by facile cyclic voltammetric deposition of amorphous Ni_xP catalysts onto the three- dimensional (3D) porous CNT support. These compounds exhibit superior catalytic activity for sustained hydrogen evolution in acidic, neutral, and basic media. In particular, the Ni_xP/CNT electrodes generate cathodic currents of 10 and 100 mA∙cm^-2 at overpotentials of 105 and 226 mV, respectively, in a 1 M phosphate buffer solution (pH = 6.5) with a Tafel slope of 100 mV∙dec^-1; the currents were stable for over 110 h without obvious decay. Our results suggest that the 3D porous CNT electrode supports could serve as a general platform for earth-abundant HER catalysts for the development of highly efficient electrodes for hydrogen production.