No abstract

A new semi-interpenetrating polymer network (semi-IPN) slow-release fertilizer (SISRF) with water absorbency, based on the kaolin-g-poly(acrylic acid-co-acrylic amide) (kaolin-g-P(AA-co-AM)) network and linear urea-formaldehyde oligomers (UF), was prepared by solution polymerization. Nutrients phosphorus and potassium were supplied by adding dipotassium hydrogen phosphate during the preparation process. The structure and properties of SISRF were characterized by various characterization methods. SISRF showed excellent water absorbency of 68 g g in tap water. The slow-release behavior of nutrients and water-retention capacity of SISRF were also measured. Meanwhile, the swelling kinetics was well described by a pseudo-second-order kinetics model. Results suggested the formation of SISRF with simultaneously good slow-release and water-retention capacity, which was expected to apply in modern agriculture and horticulture.

Copper catalysts are widely studied for the electroreduction of carbon dioxide (CO2) to value‐added hydrocarbon products. Controlling the surface composition of copper nanomaterials may provide the electronic and structural properties necessary for carbon‐carbon coupling, thus increasing the Faradaic efficiency (FE) towards ethylene and other multi‐carbon (C2+) products. Synthesis and catalytic study of silver‐coated copper nanoparticles (Cu@Ag NPs) for the reduction of CO2 are presented. Bimetallic CuAg NPs are typically difficult to produce due to the bulk immiscibility between these two metals. Slow injection of the silver precursor, concentrations of organic capping agents, and gas environment proved critical to control the size and metal distribution of the Cu@Ag NPs. The optimized Cu@Ag electrocatalyst exhibited a very low onset cell potential of −2.25 V for ethylene formation, reaching a FE towards C2+ products (FEC2+) of 43% at −2.50 V, which is 1.0 V lower than a reference Cu catalyst to reach a similar FEC2+. The high ethylene formation at low potentials is attributed to enhanced CC coupling on the Ag enriched shell of the Cu@Ag electrocatalysts. This study offers a new catalyst design towards increasing the efficiency for the electroreduction of CO2 to value‐added chemicals.

A new granular, slow-release fertilizer prepared by a cold-extrusion strategy (GSRFEx) based on urea-formaldehyde (UF), ammonium polyphosphate (APP), and amorphous silica gel (ASG) was presented. Characterizations showed that there were strong hydrogen-bond interactions and good compatibility among UF, APP, and ASG in GSRFEx. The mechanical properties as well as the slow-release properties of GSRFEx were greatly enhanced after the addition of APP and ASG to UF. Rape pot experiments indicated that GSRFEx could improve N-use efficiency dramatically and thereby facilitate the growth of rape. Importantly, as an economical, effective, and environment-friendly technology, cold extrusion has great potential to be applied in horticulture and agriculture. We hope that our work can offer an alternative method for the design of slow-release fertilizers with desirable properties.