Hanwei Wang

A simple, one-step hydrothermal approach to durable and robust superparamagnetic, superhydrophobic and electromagnetic wave-absorbing wood.

In this work, lamellar MnFe2O4 was successfully planted on a wood surface through the association of hydrogen bonds via the one-pot hydrothermal method. Simultaneously, the fluoroalkylsilane (FAS-17) on the surface of the MnFe2O4 layer formed long-chain or network macromolecules through a poly-condensation process and provided a lower surface energy on the wood surface. The MnFe2O4/wood composite (FMW) presented superior superparamagnetism, superhydrophobicity and electromagnetic wave absorption performance. The results indicated a saturation magnetization of the FMW with excellent superparamagnetism of 28.24 emu·g−1. The minimum value of reflection loss of the FMW reached −8.29 dB at 16.39 GHz with a thickness of 3 mm. Even after mechanical impact and exposure to corrosive liquids, the FMW still maintained a superior superhydrophobicity performance.

Cellulose as an adhesion agent for the synthesis of lignin aerogel with strong mechanical performance, Sound-absorption and thermal Insulation

The lignin aerogels that are both high porosity and compressibility would have promising implications for bioengineering field to sound-adsorption and damping materials; however, creating this aerogel had a challenge to adhesive lignin. Here we reported cellulose as green adhesion agent to synthesize the aerogels with strong mechanical performance. Our approach—straightforwardly dissolved in ionic liquids and simply regenerated in the deionized water—causes assembly of micro-and nanoscale and even molecule level of cellulose and lignin. The resulting lignin aerogels exhibit Young’s modulus up to 25.1 MPa, high-efficiency sound-adsorption and excellent thermal insulativity. The successful synthesis of this aerogels developed a path for lignin to an advanced utilization.

A 3D titanate aerogel with cellulose as the adsorption-aggregator for highly efficient water purification

Making full use of the hydrophilicity, hydroxyl reactivity, high strength and stiffness, low weight and biodegradability of cellulose, a novel cellulose-based adsorption-aggregator is creatively exploited. In this work, a 3D titanate aerogel with cellulose as the adsorption-aggregator has been fabricated for highly efficient water purification. Herein, the polyhydric cellulose not only acts as a crosslinking agent, but also facilitates ion-induced aggregation, which strongly promotes the adsorption efficiency of the titanate and effectively improves its inherent shortcomings as an inorganic adsorbent. The Pb2+, Sr2+, Cu2+, Ra2+, and Cd2+ adsorption capacities surprisingly reach 2.46, 1.43, 2.51, 1.22, and 1.98 mmol g−1, respectively. Moreover, it may be applied in the fields of water purification agents, oxidants, catalysts, disinfectants and photoelectrochemical components, in view of the hydroxyl oxidation, hydroxyl induction, disinfection, and water purification abilities of cellulose. Therefore, the development of cellulose adsorption-aggregating agents is both reasonable and of great value.

One-step solvothermal deposition of ZnO nanorod arrays on a wood surface for robust superamphiphobic performance and superior ultraviolet resistance

In the present paper, uniformly large-scale wurtzite-structured ZnO nanorod arrays (ZNAs) were deposited onto a wood surface through a one-step solvothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and differential thermal analysis (DTA). ZNAs with a diameter of approximately 85 nm and a length of approximately 1.5 μm were chemically bonded onto the wood surface through hydrogen bonds. The superamphiphobic performance and ultraviolet resistance were measured and evaluated by water or oil contact angles (WCA or OCA) and roll-off angles, sand abrasion tests and an artificially accelerated ageing test. The results show that the ZNA-treated wood demonstrates a robust superamphiphobic performance under mechanical impact, corrosive liquids, intermittent and transpositional temperatures, and water spray. Additionally, the as-prepared wood sample shows superior ultraviolet resistance.

Naturally three-dimensional laminated porous carbon network structured short nano-chains bridging nanospheres for energy storage

The electrode material is the core component of an energy storage system and determines the ultimate electrochemical performance. There is an urgent demand for carbon nanomaterials with unique structures for applications as the anode of lithium-ion batteries and supercapacitor electrodes. Here, we synthesize three-dimensional laminated porous carbon aerogels (CAs), composed of carbon nanospheres bridged with short carbon chains, by using simple annealing processes inspired by the natural structure of the kiwifruit as a precursor. The carbon material obtained at 800 °C (CA-800) exhibits a high lithium storage capacity (504.8 mA h g−1 at 100 mA g−1) and specific capacitance (337.4 F g−1 in the three-electrode electrochemical configuration and 322.9 F g−1 in a symmetric two-electrode supercapacitor cell at a current density of 0.5 A g−1). Moreover, extensible and flexible symmetric supercapacitors obtained using CA-800 display stable electrochemical performance after a folding test with different curvatures and even 10 000 cycles of a bending test. This study considers a fascinating route of producing excellent electrode materials and energy storage devices derived from inexpensive, sustainable, and available natural resources.

Bio-Inspired nacre-like nanolignocellulose-poly (vinyl alcohol)-TiO 2 composite with superior mechanical and photocatalytic properties

Nacre, the gold standard for biomimicry, provides an excellent example and guideline for assembling high-performance composites. Inspired by the layered structure and extraordinary strength and toughness of natural nacre, nacre-like nanolignocellulose/poly (vinyl alcohol)/TiO2 composites possessed the similar layered structure of natural nacre were constructed through hot-pressing process. Poly (vinyl alcohol) and TiO2 nanoparticles have been used as nanofillers to improve the mechanical performance and synchronously endow the superior photocatalytic activity of the composites. This research would be provided a promising candidate for the photooxidation of volatile organic compounds also combined with outstanding mechanical property.

Self-photodegradation of formaldehyde under visible-light by solid wood modified via nanostructured Fe-doped WO3 accompanied with superior dimensional stability

In this paper, solid wood with superior self-photodegradation of formaldehyde (HCHO) under visible-light was realized through a facile method at room temperature. Spherical Fe-doped WO3 nanostructured materials deposited on the wood substrate with diameters ranging from 100 to 150nm were mainly responsible for the self-photodegradation of formaldehyde. Fe-doped WO3 nanostructured materials were strongly adhered to wood surface through electrostatic and hydrogen bonding interactions. Additionally, the dimensional stability and the inherent anisotropic thickness swelling of wood were greatly improved and eliminated, respectively. Interestingly, a wood rabbit craft was also designed and showed a good visible-light-driven photocatalytic performance in a relatively larger area for different concentrations of HCHO. The research result would both fabricate a novel catalyst for the degradation of the hazardously gaseous pollutants and basically improve the wood intrinsic performance.

Cellulose Fibers Constructed Convenient Recyclable 3D Graphene-Formicary-like δ-Bi2O3 Aerogels for the Selective Capture of Iodide

Radioiodine is highly radioactive and acutely toxic, which can be a serious health threat, and requires effective control. To fully utilize an adsorbent and reduce the overall production cost, successive recycling applications become necessary. Here, 3D formicary-like δ-Bi2O3 (FL-δ-Bi2O3) aerogel adsorbents were synthesized using a one-pot hydrothermal method. In this hybrid structure, abundant flowerlike δ-Bi2O3 (MR-δ-Bi2O3) microspheres were inlaid into the interconnected ant nest channel, forming a 3D hierarchical structure, which is applied as an efficient adsorbent with easy recovery for radioiodine removal. Notably, the FL-δ-Bi2O3 aerogel adsorbent exhibited a very high uptake capacity of 2.04 mmol/g by forming an insoluble Bi4I2O5 phase. Moreover, the FL-δ-Bi2O3 worked in a wide pH range of 4-10 and displayed fast uptake kinetics and excellent selectivity due to the 3D porous interconnected network and larger specific surface area. Importantly, the recycling process is easy, using only tweezers to directly move the 3D aerogel adsorbents from one reaction system to another. Therefore, the FL-δ-Bi2O3 aerogel may be a promising practical adsorbent for the selective capture of radioactive iodide.

Stress sensitive electricity based on Ag/cellulose nanofiber aerogel for self-reporting

A self-reporting aerogel toward stress sensitive slectricity (SSE) was presented using an interconnected 3D fibrous network of Ag nanoparticles/cellulose nanofiber aerogel (Ag/CNF), which was prepared via combined routes of silver mirror reaction and ultrasonication. Sphere-like Ag nanoparticles (AgNPs) with mean diameter of 74nm were tightly anchored in the cellulose nanofiber through by the coherent interfaces as the conductive materials. The as-prepared Ag/CNF as a self-reporting material for SSE not only possessed quick response and sensitivity, but also be easily recovered after 100th compressive cycles without plastic deformation or degradation in compressive strength. Consequently, Ag/CNF could play a viable role in self-reporting materials as a quick electric-stress responsive sensor.

Mesopore-dominant nitrogen-doped carbon with a large defect degree and high conductivity via inherent hydroxyapatite-induced self-activation for lithium-ion batteries

In this study, N-doped mesopore-dominant carbon (NMC) materials were prepared using bio-waste tortoise shells as a carbon source via a one-step self-activation process. With intrinsic hydroxyapatites (HAPs) as natural templates to fulfill the synchronous carbonization and activation of the precursor, this highly efficient and time-saving method provides N-doped carbon materials that represent a large mesopore volume proportion of 74.59%, a high conductivity of 4382 m S−1, as well as larger defects, as demonstrated by Raman and XRD studies. These features make the NMC exhibit a high reversible lithium-storage capacity of 970 mA h g−1 at 0.1 A g−1, a strong rate capability of 818 mA h g−1 at 2 A g−1, and a good capacity of 831 mA h g−1 after 500 cycles at 1 A g−1. This study provides a highly efficient and feasible method to prepare renewable biomass-derived carbons as advanced electrode materials for the application of energy storage.