Melamine-assisted solvothermal synthesis of PtNi nanodentrites as highly efficient and durable electrocatalyst for hydrogen evolution reaction.

Rational design of highly efficient and durable electrocatalysts for hydrogen evolution reaction (HER) is of prime importance for renewable and sustainable energy. Herein, PtNi nanodentrites (PtNi NDs) were facilely synthesized in oleylamine (OAm) by a one-pot solvothermal method, using melamine and cetyltrimethylammonium chloride (CTAC) as co-structure-directing agents. The obtained catalyst showed superior catalytic activity and enhanced durability for HER relative to commercial Pt/C, home-made PtNi3 nanocrystals (NCs) and Pt3Ni NCs both in alkaline and acidic media. The enhanced HER activities are attributed to bimetallic synergies and interface structures in PtNi NDs. This work provides an effective strategy to prepare highly efficient and durable electrocatalysts for HER.

Poly-l-lysine mediated synthesis of palladium nanochain networks and nanodendrites as highly efficient electrocatalysts for formic acid oxidation and hydrogen evolution.

The morphology- and size-tunable synthesis of nanocatalysts has attracted substantial research interest especially in catalysis. In this work, we synthesized free-standing Pd nanochain networks (Pd NCNs) and Pd nanodendrites (Pd NDs) through a direct poly-l-lysine (PLL)-mediated one-pot aqueous method. The presence of PLL and its concentrations were critical in this regard, showing PLL as the structure-directing and capping agents during the nucleation and crystal growth procedures. The synthesized architectures exhibited improved catalytic activity and enhanced durability towards formic acid oxidation and hydrogen evolution reactions relative to commercial Pd black catalyst. Moreover, the electrochemical active surface area and the electrocatalytic performance of Pd NCNs were dramatically enhanced in comparison to Pd NDs mainly owing to the unique network-like structure of Pd NCNs.

Theophylline-assisted, eco-friendly synthesis of PtAu nanospheres at reduced graphene oxide with enhanced catalytic activity towards Cr(VI) reduction.

Theophylline as a naturally alkaloid is commonly employed to treat asthma and chronic obstructive pulmonary disorder. Herein, a facile theophylline-assisted green approach was firstly developed for synthesis of PtAu nanospheres/reduced graphene oxide (PtAu NSs/rGO), without any surfactant, polymer, or seed involved. The obtained nanocomposites were applied for the catalytic reduction and removal of highly toxic chromium (VI) using formic acid as a model reductant at 50°C, showing the significantly enhanced catalytic activity and improved recyclability when compared with commercial Pt/C (50%) and home-made Au nanocrystals supported rGO (Au NCs/rGO). It demonstrates great potential applications of the catalyst in wastewater treatment and environmental protection. The eco-friendly route provides a new platform to fabricate other catalysts with enhanced catalytic activity.

Facile synthesis of porous bimetallic alloyed PdAg nanoflowers supported on reduced graphene oxide for simultaneous detection of ascorbic acid, dopamine, and uric acid.

Porous bimetallic alloyed palladium silver (PdAg) nanoflowers supported on reduced graphene oxide (PdAg NFs/rGO) were prepared via a facile and simple in situ reduction process, with the assistance of cetyltrimethylammonium bromide as a structure directing agent. The as-prepared nanocomposite modified glassy carbon electrode (PdAg NFs/rGO/GCE) showed enhanced catalytic currents and enlarged peak potential separations for the oxidation of ascorbic acid (AA), dopamine (DA), and uric acid (UA) as compared to those of PdAg/GCE, rGO/GCE, commercial Pd/C/GCE, and bare GCE. The as-developed sensor can selectively detect AA, DA, and UA with a good anti-interference ability, wide concentration ranges of 1.0 µM-2.1 mM, 0.4-96.0 µM, and 1.0-150.0 µM, respectively, together with low detection limits of 0.057, 0.048, and 0.081 µM (S/N = 3), respectively. For simultaneous detection of AA, DA, and UA, the linear current-concentration responses were observed from 1.0 µM-4.1 mM, 0.05-112.0 µM, and 3.0-186.0 µM, with the detection limits of 0.185, 0.017, and 0.654 µM (S/N = 3), respectively.