Boosting Electrocatalytic Nitrate-to-Ammonia Conversion via Plasma Enhanced CuCo Alloy–Substrate Interaction

Electrocatalytic conversion of widely distributed nitrate from industrial wastewater into value-added ammonia was proposed as an attractive and sustainable alternative to harvesting green ammonia. Herein, CuCo alloys were facilely synthesized for nitrate conversion, while nonthermal Ar-plasma was employed to enhance the adhesion strength between the electrocatalyst and substrate interface via regulating the surface hydrophobicity and roughness. Based on Ar-plasma treatment, a high ammonia yield rate (5129.29 μg cm-2 h-1) was achieved using Cu30Co70 electrocatalyst -0.47 V vs RHE, while nearly 100% of Faradaic efficiency was achieved using Cu50Co50 electrocatalyst at -0.27 V vs RHE (reversible hydrogen electrode). Validated by in situ spectroscopy and density functional theory calculations, the high activity of the CuCo alloy was derived from the regulation of Co to weaken the strong adsorption capacity of Cu and the shift of the d-band center to lower the energy barrier, while Ar-plasma modification promoted the formation of *NO to boost nitrate conversion

Controlling the Size and Film Strength of Individualized Cellulose Nanofibrils Prepared by Combined Enzymatic Pretreatment and High Pressure Microfluidization

The production of functionalized polymers from biomass is of great interest. Cellulose nanofibrils (CNFs) isolated from lignocellulose have great potential in novel functional materials. In the present study, mild enzymatic treatment followed by high pressure microfluidization of a bleached softwood kraft pulp led to the release of individualized CNFs. Disk milling and high pressure microfluidization resulted in entangled networks of CNFs. CNFs from mild enzyme pretreatments were 8 to 12 nm in diameter and 200 to 400 nm in length, while CNFs from pure mechanical pretreatment were an entangled network of nanofibrils with a diameter of 10 to 20 nm. Films prepared from the resulting CNFs were flexible and semitransparent, and they exhibited high specific tensile stress and modulus. The specific tensile stress and modulus were increased by 3- to 5-fold and 5- to 11-fold, respectively. The specific tensile modulus of the CNFs films from mild enzyme treatments followed by microfluidization was approximately 15 to 16 MN·m/kg, while that of CNFs from pure mechanical fibrillation with or without microfluidization was 10 MN·m/kg and 14 MN·m/kg, respectively. The specific tensile strength of the CNFs films from mild enzyme treatment was slightly lower (72 to 98 kN·m/kg) than that of the CNFs films from pure mechanical fibrillation