Junya Cao,Fenggang Han,Liguo Wang,Xiaoyu Huang,Yan Cao,Peng He,Huanhuan Yang,Jiaqiang Chen,Huiquan Li
A series of Ru/g-C3N4 materials with highly dispersed Ru were firstly prepared by an ultrasonic impregnation method using carbon nitride as a support. The catalysts were characterized by various techniques including BET and elemental analysis, ICP-AES, XPS, XRD, CO2-TPD and TEM. The results demonstrated that Ru/g-C3N4 materials with a mesoporous structure and highly dispersed Ru were successfully prepared. The chemo-selective hydrogenation of p-phenylenediamine (PPDA) to 1,4-cyclohexanediamine (CHDA) over Ru/g-C3N4 as a model reaction was investigated in detail. PPDA conversion of 100% with a CHDA selectivity of more than 86% could be achieved under mild conditions. It can be inferred that the carbon nitride support possessed abundant basic sites and the Ru/g-C3N4-T catalysts provided suitable basicity for the aromatic ring hydrogenation. Compared to the N-free Ru/C catalyst, the involvement of nitrogen species in Ru/g-C3N4 remarkably improved the catalytic performance. In addition, the recyclability of the catalyst demonstrated that the aggregation of Ru nanoparticles was responsible for the decrease of the catalytic activity. Furthermore, this strategy also could be expanded to the selective hydrogenation of other aromatic diamines to alicyclic diamines.
Considering the potential misuse of antibiotics to improve the yield and economic benefits in the production of animal-derived foods such as milk, the development of a simple, label-free, precise, reliable, low-cost, and onsite assay for antibiotic residues is highly desirable to ensure food safety. In this scenario, we here proposed a hybrid oxidase-mimicking nanozyme of the Ru@g-C3N4 nanosheet that combines with 3,3′,5,5′-tetramethylbenzidine (TMB) to develop a blocking oxidase-mimicking activity-driven photothermal and colorimetric synergistic sensing platform for intelligent onsite detection of tetracycline antibiotics (TCs). In the absence of TCs, the prominent oxidase-mimicking activity of Ru@g-C3N4 rapidly catalyzed colorless TMB to dark-blue oxTMB, accompanied by the appearance of an obvious absorbance enhancement at 655 nm and a remarkable photothermal signal upon 660 nm laser irradiation. Conversely, the remaining TCs effectively blocked this chromogenic reaction because of the π–π stacking of its tetraphenyl skeleton with the Ru@g-C3N4 nanozyme to block the affinity of TMB to the catalytic active site inside Ru@g-C3N4. Based on this, a TCs residual level-dependent photothermal and colorimetric signal synergistic decrease sensing platform was developed with the assistance of a 660 nm laser-assisted hand-held thermal imager and a Color Picker APP-inbuilt smartphone, which demonstrated the intelligent onsite label-free, reliable, and precise detection of TCs in real milk samples with acceptable results. Notably, this oxidase-mimicking nanozyme-based dual-mode sensing platform provided a built-in cross-reference correction to improve not only the accuracy but also the reliability for TC detection in milk, which showed a vast promise in the further development of commercial point-of-care testing to achieve early warning of antibiotic residues to ensure the quality and safety of animal-derived foodstuffs.
Shuxing Zhang,Jiali Zheng,Zhihui Li,Xiaoshu Ding,Yanji Wang
Herein, we reported a green catalytic reaction system for the synthesis of 5-amino-1-pentanol with furfural and ionic liquid hydroxylamine salt as the initial raw material. In addition, the method can obtain 2-furonitrile and furfurylamine in high yields. The reaction system comprises three new reactions, including the reaction of furfural with ionic liquid hydroxylamine salt to synthesize 2-furonitrile, the hydrogenation of 2-furonitrile to prepare furfurylamine, and the hydrogenolysis of furfurylamine to prepare 5-amino-1-pentanol. For the synthesis of 2-furonitrile, ionic liquid hydroxylamine salt (NH 2 OH) 2 ·[HSO 3 - b - mim ]·HSO 4 was prepared. The ionic liquid as co-solvents, catalysts, and hydroxylamine stabilizer has recovery and reusability. For the hydrogenation of 2-furonitrile to furfurylamine, high-efficiency Ru/g-C 3 N 4 catalyst was prepared. For the hydrogenolysis of furfurylamine to 5-amino-1-pentanol, high-efficiency Pt/ZrO 2 catalyst was prepared. Finally, the yield of 5-amino-1-pentanol based on furfural was 48.7%. A potential pathway for preparing drugs from biomass has been identified in this work.