Selectively attaching Pt-nano-clusters to the open ends and defect sites on carbon nanotubes for electrochemical catalysis

Microporous N,P-Codoped Graphitic Nanosheets as an Efficient Electrocatalyst for Oxygen Reduction in Whole pH Range for Energy Conversion and Biosensing Dissolved Oxygen

Microporous N,P-codoped graphitic nanosheets (N,P-CMP-1000) were synthesized by thermal annealing (1000 °C) of as-synthesized conjugated microporous polymers (CMPs) in the presence of phytic acid, which can be used as an effective metal-free electrocatalyst for the oxygen reduction reaction (ORR) for energy conversion. In the whole pH range (i.e. alkaline, acidic, and neutral solutions), the obtained N,P-CMP-1000 exhibits superior electrocatalytic activity for ORR with a low overpotential, high current density, and good stability. Furthermore, N,P-CMP-1000 can also be applied for electrochemically sensing dissolved oxygen (DO), with a high sensitivity (1.89 μA mg^-1  L) and broad detection range (2.56 to 16.65 mg L^-1 ) due to its good electrocatalytic performance towards ORR in neutral solution. In vitro cytotoxicity tests (CCK-8 and Live/Dead Cell Double Staining Assay) of N,P-CMP-1000 extracts demonstrated its good biocompatibility to Human Corneal Epithelial Cells (HCEC), which shows its great potential as an eye-wearable biosensor for sensing DO in tears.

Pt-MWCNT modified carbon electrode strip for rapid and quantitative detection of H2O2 in food

A single-use screen-printed carbon electrode strip was designed and fabricated. Nanohybrids, prepared by deposition of platinum (Pt) nanoparticles on multi-wall carbon nanotube (MWCNT), was modified on the surface of screen-printed carbon electrode for the development of a fast, sensitive and cost-effective hydrogen peroxide (H2O2) detection amperometric sensor strip. With Pt-MWCNT nanohybrids surface modification, current generated in response to H2O2 by the screen-printed carbon electrode strip was enhanced 100 fold with an applied potential of 300 mV. Quality of as-prepared electrode strip was assured by the low coefficient of variation (CV) (<5%) of currents measured at 5 s. Three linear detection ranges with sensitivity of 75.2, 120.7, and 142.8 μA mM-1 cm-2 were observed for H2O2 concentration in the range of 1-15 mM, 0.1-1 mM, and 10-100 μM, respectively. The lowest H2O2 concentration could be measured by the as-prepared strip was 10 μM. H2O2 levels in green tea infusion and pressed Tofu could be rapidly detected with results comparable to that measured by ferrous oxidation xylenol orange (FOX) assay and peroxidase colorimetric method.

Highly Ordered Hierarchical Pt and PtNi Nanowire Arrays for Enhanced Electrocatalytic Activity toward Methanol Oxidation

Highly ordered hierarchical Pt and PtNi nanowire arrays were prepared using CdS hierarchical nanowire arrays (HNWAs) as sacrificial templates and demonstrated high electrochemical active surface areas. For the resulting Pt HNWAs sample, the peak current for methanol oxidation at +0.74 V was almost 1 order of magnitude higher than that of Pt solid nanowire arrays prepared in a similar manner but without the use of CdS template, and the addition of a Ni cocatalyst effectively enhanced the tolerance against CO poisoning. The results demonstrated that highly ordered Pt and PtNi HNWAs may be exploited as promising anode catalysts in the application of direct methanol fuel cells.

Fabrication and performance evaluation of a novel membrane electrode assembly for DMFCs

In this study, a new GDL was prepared using graphene–PVC–PANI and teflonated carbon cloth. PdNPs and nanosized LaNi_0.5Fe_0.5O₃NPs-CH was synthesized. A DMFC were designed, assembled and tested with the suggested nanoparticles and GDL.

Improvement of Amperometric Biosensor Performance for H2O2Detection based on Bimetallic PtM (M = Ru, Au, and Ir) Nanoparticles

Novel bimetallic nanoparticles have been synthesized via rapid microwave irradiation, leading to an improved sensitivity and a highly anti-interference property for amperometric biosensor in H2O2detection. The material characterizations were performed by TEM, XRD, and EDX, which show the bimetallic formation of Pt-based catalysts and well-dispersed nanoparticles of 2–5 nm. The sensitivities for the detection of H2O2of PtRu, PtAu, and PtIr as the biosensor working electrode catalysts are 539.01 (R2=0.99), 415.46 (R2=0.99), and 404.52 (R2=0.97) μA mM−1 cm-2, respectively, nearly twice higher than the pure Pt catalyst (221.77 μA mM−1 cm−2,R2=0.98), at a low applied potential of +0.25 V versus Ag/AgCl. Furthermore, Pt-Ru and Pt-Ir show a highly sensitive response and a promising anti-interference capability to ascorbic acid, a major interferent, by reducing the interferent current as low as 7-8% significantly lower than that of Pt (30% change). The enhancement of both sensitivity and selectivity in the bimetallic catalysts can be found practical applications in biosensing.