A degradable dual lignocellulosic fiber with superwetting characteristics was successfully fabricated by a strategically adjusted condensation reaction of melamine and formaldehyde, maintaining high efficiency for oil/water mixture separation.

Carbon dots (CDs) can be widely used in the field of sensing because of its good water solubility, low toxicity, high fluorescence stability and excellent biocompatibility. It has become a popular trend to prepare high-value, inexpensive, renewable and environmentally friendly CDs sensors from biomass resources. This article reviewed the research progress of biomass-derived CDs as chemical, physical and biological sensors in recent years and studied their preparation processes and sensing abilities. Furthermore, the prospects and challenges of biomass-CDs sensors were discussed. This article is expected to provide inspirations for the design, preparation and application of biomass-CDs sensors in the future.

Superhydrophobic surfaces have received increasing attention in a broad range of important fields including oily wastewater treatment and oil collection in spills accidents. However, the preparation of such superhydrophobic surfaces has been proven to be energy-intensive and these surfaces are non-degradable. Herein, a naturally abundant fibrous substrate (i.e., lignocellulosic fibers and cotton fabric), mainly composed of cellulose, combining inexpensive bulk chemicals (melamine, formaldehyde, and octadecylamine) was cleverly designed and strategically exploited for the low-cost, easy scale-up, and eco-friendly superhydrophobic surface. These superhydrophobic surfaces can be used to clean different forms of oil-contaminations, including floating light-oil and sedimentary heavy-oil (with an efficiency above 700 wt% for various oils). This study showed that the superhydrophobic surfaces created via a scalable and green water solvent-assisted condensation reaction can achieve high water repellency both in air and in oil, and exhibited a single efficient avenue for gravity-driven active filtration of oil. The superhydrophobicity of the octadecylamine–melamine–formaldehyde (OMF) lignocellulosic fibers remained unperturbed even after long-term exposure to UV radiation (at both 254 nm and 365 nm) for 168 h. The OMF lignocellulosic fibers showed good antifouling properties and maintained high separation efficiency (>95%) as well as a high water contact angle (>150°) after being repeatedly used for 70 cycles. Furthermore, this strategy exhibited good versatility for superhydrophobic cotton fabrics with high contact angles (>160°) and high water/oil separation efficiency (96%).