Custom-designed polyphenol lignin for the enhancement of poly(vinyl alcohol)-based wood adhesive.

Adhesives are used extensively in the wood industry. As resource and environmental issues become increasingly severe, the development of green and sustainable biomass-based adhesives has attracted increasing attention. In this work, a green wood adhesive is developed from poly(vinyl alcohol) and lignin with molecular designs of lignin extending beyond those in nature. The lignin undergoes extraction from corncob residue, aldehydration, and phenolisation (phenol, resorcinol, and catechol) to significantly increase the phenolic hydroxyl groups (over 7.92 mmol/g), which has the effect of enhancing the hydrogen bonding force between the adhesive and the wood, thereby greatly improving adhesive performance. Compared with pure PVA, polyphenol lignin-containing PVA showed improved adhesion strength and hydrophobicity. PVA/resorcinol-lignin has the significantly improved wood lap shear strength (6.27 MPa, 77.6 % improvement) and hydrophobicity (almost 100 % increase in wet shear strength). This research not only provides a green and high-performance alternative raw material for wood adhesives but also broadens the path for large-scale application of biomass.

Biomass-derived carbon dots regulating nickel cobalt layered double hydroxide from 2D nanosheets to 3D flower-like spheres as electrodes for enhanced asymmetric supercapacitors.

Layered double hydroxides (LDHs) often require the use of carbon materials to improve their stability, conductivity, and specific surface area to accommodate new directions in the development of high-performance energy storage materials. Herein, 2D nickel cobalt layered double hydroxide (NCLDH) nanosheets are regulated to form 3D flower-like spheres by fungus bran-derived carbon dots (CDs) via an in situ growth method. The prepared sample (CDs/NCLDH) shows abundant accessible active sites and favorable electrical conductivity, which is aided by strong interactions between CDs and NCLDH. The optimized CDs/NCLDH exhibits significantly enhanced electrochemical performances, including ultrahigh specific capacitance (2100F g-1 at 1 A g-1) and a great rate capability, which are two times higher than those of the NCLDH electrode. Additionally, the asymmetric supercapacitor device assembled with the CDs/NCLDH positive electrode and the fungus bran-derived activated carbon (FBC) negative electrode achieves a superior energy density of 52.5 Wh kg-1 at an ultrahigh powder density of 750 W kg-1. With their simple synthesis method and excellent electrochemical performance, the role of the CDs provides new insights for the development of LDHs with improved performance.

Biomimetic nitrogen-rich photocatalyst based on cadmium sulfide for photocatalytic hydrogen evolution.

A novel N-rich sugarcane-like photocatalyst CdS/C3N5 (CCN) was prepared by a thermal polymerization method and tested for generating H2 and realizing antiphotocorrosive performance. The best photocatalytic H2 evolution is obtained for a CdS to C3N5 mass ratio of 1:1 (CCN3), which is nearly 33 and 3 times higher than that of pure C3N5 and CdS, respectively. CCN3 can be used to effectively reduce CdS photocorrosion and increase stability because of its N-rich performance and sugarcane-like structure, which can affect electron transport and enhance the internal binding force, respectively. CCN3 can maintain a high H2 evolution ability after 5 cycles, while still maintaining the original sugarcane-like shape, which has an anti-photocorrosive ability.

N,S-self-doped carbon quantum dots from fungus fibers for sensing tetracyclines and for bioimaging cancer cells.

In this work, nitrogen and sulfur dual-doped carbon quantum dots (N,S-CDs) from naturally renewable biomaterial fungus fibers were prepared by a biosynthesis and hydrothermal method. The N,S-CDs displayed good water solubility, excellent stability, high quantum yield (QY = 28.11%) as well as remarkable features for fluorescence quenching-based detection and cellular imaging of cancer cells. It was worth mentioning that the heteroatoms doped carbon quantum dots made from the fungus fibers had a satisfactory QY and could be used as a selective, efficient, and sensitive fluorescent probe to determine tetracyclines by the synergistic effects of static quenching and internal filtration effect. The probe demonstrated a wide linear range and low detection limit. For tetracycline, the linear range was 0.5 µM to 47.6 µM, and the corresponding detection limit was 15.6 nM. Significantly, the test papers prepared by using N,S-CDs could detect tetracyclines in aquiculture wastewater rapidly. The produced N,S-CDs did not affect the cell viability and showed great promises for cellular imaging.

Biomass-derived nitrogen-doped carbon quantum dots: highly selective fluorescent probe for detecting Fe3+ ions and tetracyclines.

Nitrogen-doped carbon quantum dots (N-CQDs) were successfully synthesized using rice residue and glycine as carbon and nitrogen sources by one-step hydrothermal method. High quantum yield (23.48%) originated from the effective combination of nitrogen with various functional groups (CO, NH, CN, COOH and COC). The N-CQDs showed a fluorescence with the wavelength varied from 420 to 500 nm and the maximum emission wavelength being at 440 nm. N-CQDs have been importantly applied as probe to detect Fe3+ and tetracycline (TCs) antibiotics with remarkable performance. Using the linear relationship between fluorescence intensity and Fe3+ concentration, the N-CQDs could be employed as a simple, efficient sensor for ultrasensitive Fe3+ detection ranging from 3.32 to 32.26 µM, with a limit of detection (LOD) of 0.7462 µM. The N-CQDs showed the applicability to detect TCs. The detection limits of tetracycline, terramycin and chlortetracycline were 0.2367, 0.3739 and 0.2791 µM, respectively. The results of TC by fluorescence method in real water samples were in good agreement with standard Ultraviolet-visible (UV-vis) method. The N-CQDs have various potential applications including sensitive and selective detection of Fe3+ and TCs, and cellular imaging with low cytotoxicity, good biocompatibility and high permeability.