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Shao, Qian

Publications and source records attributed to Shao, Qian.

Anchoring carbon nanotubes and post-hydroxylation treatment enhanced Ni nanofiber catalysts towards efficient hydrous hydrazine decomposition for effective hydrogen generation

For effective hydrogen generation with remarkable durability, carbon nanotubes (CNTs) grown on Ni nanofibers and their post hydroxylation treatment engendered active Ni nanofiber catalysts an efficient decomposition of hydrous hydrazine with a turnover frequency (TOF) of 19.4 h -1 and an activation energy down to 51.05 KJ mol -1 .

08 HYDROGEN↗

Poly(sulfur-random-(1,3-diisopropenylbenzene)) based mid-wavelength infrared polarizer: Optical property experimental and theoretical analysis

Development of polymer based mid-wavelength infrared (MWIR) optics has been limited mainly due to high optical loss of organic polymers used in general optical components. In this study, a MWIR polarization grating based on a sulfuric polymer poly(sulfur-random-(1,3-diisopropenylbenzene)) with a low loss in the MWIR range was fabricated using a simple two-step process: imprint and metal deposition. Fourier-transform infrared (FTIR) spectroscopy measurement showed that this polymeric MWIR polarizer selectively transmitted the polarized IR in transverse magnetic (TM) mode over the transverse electric (TE) mode at normal incidence. The measured extinction ratios ( η = The ratio of transmissions in TM and TE) were 208, 176, and 212 at the wavelength of 3, 4, and 5 μm, respectively. The computational simulation and analytical model confirmed that the enhanced TM transmission efficiency and η followed a Fabry-Pérot (FP) resonance mode within the created sulfuric polymer film. This polymeric MWIR polarizer demonstrated a great potential for broader applications in IR photonics to realize low-cost and durable optical components.

42 ENGINEERING↗

Achieving superior electromagnetic wave absorbers through the novel metal-organic frameworks derived magnetic porous carbon nanorods

High absorption capacity and broad absorption bandwidth electromagnetic wave (EMW) absorption materials (namely, EMW absorbers) are highly desirable due to the interference with electronics and harms on human beings’ health. In search for rational design on nanostructured absorbers, we have synthesized and demonstrated the rod-shape composites with Fe-containing magnetic nanoparticles (Fe 3 O 4 , Fe 3 C and Fe NPs) embedded into nano-porous carbon (NPC) through pyrolysis of Fe-based metal-organic frameworks (MOFs). The morphologies, compositions, and graphitization degree of the Fe-MOFs derived magnetic NPC nanorods can be effectively controlled via adjusting the pyrolysis temperatures. The graphitization level has a significant influence on the permittivity of the composites upon variation of pyrolysis temperatures, thereby a tunable electromagnetic wave (EMW) absorption is observed. Consequently, the resulting magnetic NPC nanorods obtained at pyrolysis temperature of 600 and 700 °C exhibit the most remarkable EMW absorption performance with a strong reflection loss of -52.9 dB and broad effective bandwidth (f e ) of 4.64 GHz at 3.07 mm. With a thickness of 3.5 mm, the f e for the magnetic NPC nanorods at 600 °C covers the whole X-band from 7.92 to 12.48 GHz. Finally, the noticeable EMW absorption performances have been greatly enhanced compared to those reported Fe 3 O 4 based absorbers, owing to the synergy of multiple components and the porous structures inherited from MOFs.

36 MATERIALS SCIENCE↗

Iridium-based Catalysts for Electrocatalytic Water Splitting

We report that chemical energy conversion/storage through water splitting for hydrogen production has been recognized as the ideal solution to the transient nature of renewable energy sources. Solid polymer electrolyte (SPE) water electrolysis is one of the most practical ways to produce pure H2. Electrocatalysts are key materials in the SPE water electrolysis. At anode side, electrode materials catalyzing the oxygen evolution reaction (OER) require properties. Among the reported materials, only iridium presents high activity and is more stable. In this article, an application overview of single iridium metal and its oxide catalysts; binary, ternary and multi-component catalysts of iridium oxides; and supported composite catalysts for the OER in SPE water electrolysis is presented. Two main strategies to improve the activity of an electrocatalyst system, i.e., increasing the number of active sites and the intrinsic activity of each active site were reviewed with detailed examples. Finally, the challenges and perspectives in this field are also discussed.

25 ENERGY STORAGE↗

Role of Interfaces in Two-Dimensional Photocatalyst for Water Splitting

Here, we report hydrogen generation from the direct splitting of water by photocatalysis is regarded as a promising and renewable solution for the energy crisis. The key to realize this reaction is to find an efficient and robust photocatalyst that ideally makes use of the energy from sunlight. Recently, due to the attractive properties such as appropriate band structure, ultrahigh specific surface area, and more exposed active sites, two-dimensional (2D) photocatalysts have attracted significant attention for photocatalytic water splitting. This Review attempts to summarize recent progress in the fabrication and applications of 2D photocatalysts including graphene-based photocatalysts, 2D oxides, 2D chalcogenides, 2D carbon nitride, and some other emerging 2D materials for water splitting. The construction strategies and characterization techniques for 2D/2D photocatalysts are summarized. Particular attention has been paid to the role of 2D/2D interfaces in these 2D photocatalysts as the interfaces and heterojunctions are critical for facilitating charge separation and improving photocatalysis efficiency. We also critically discuss their stability as photocatalysts for water splitting. Lastly, we highlight the ongoing challenges and opportunities for the future development of 2D photocatalysts in this exciting and still emerging area of research.

08 HYDROGEN↗

ZnFe{sub 2}O{sub 4}/TiO{sub 2} nanocomposite films for photocathodic protection of 304 stainless steel under visible light

Highlights: • Hydrothermal method for synthesizing ZnFe{sub 2}O{sub 4} nanoparticles on TiO{sub 2} NTs. • The photoelectrochemical property of TiO{sub 2} could greatly improve by doping ZnFe{sub 2}O{sub 4}. • The ZnFe{sub 2}O{sub 4}/TiO{sub 2} composite films provide a better photocathodic protection for 304SS. - Abstract: ZnFe{sub 2}O{sub 4} sensitized TiO{sub 2} nanotubes were fabricated via anodic oxidation and hydrothermal method. The ZnFe{sub 2}O{sub 4}/TiO{sub 2} composite films with different concentrations were synthesized to explore the optimal photoelectrochemical property compared with pure TiO{sub 2} nanotubes. The morphology and chemical composition of samples were characterized by scanning electron microscopy, energy-dispersive spectrometry, and X-ray diffraction. The performance of protection for 304 stainless steel was investigated by electrochemical tests, such as open circuit potential and photocurrent density. The results indicate that ZnFe{sub 2}O{sub 4}/TiO{sub 2} composite films showed efficient photocathodic protection effect for 304 stainless steel under visible light, and the optimal specimen composite films shifted the corrosion potential of 304 stainless steel to −780 mV.

36 MATERIALS SCIENCE↗

Complexation and phase evolution at dimethylformamide-Ag(111) interfaces

The interaction of solvent molecules with metallic surfaces impacts many interfacial chemical processes. We investigate the chemical and structure evolution that follows adsorption of the polar solvent dimethylformamide (DMF) on Ag(111). An Ag(DMF) 2 coordination complex forms spontaneously by DMF etching of Ag(111), yielding mixed films of the complexes and DMF. Utilizing ultrahigh vacuum scanning tunneling microscopy (UHV-STM), in combination with X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) computations, we map monolayer phases from the 2-D gas regime, consisting of a binary mixture of DMF and Ag(DMF) 2 , through the saturation monolayer limit, in which these two chemical species phase separate into ordered islands. Structural models for the near-square DMF phase and the chain-like Ag(DMF) 2 phase are presented and supported by DFT computation. Interface evolution is summarized in a surface pressure-composition phase diagram, which allows structure prediction over arbitrary experimental conditions. In conclusion, this work reveals new surface coordination chemistry for an important electrolyte-electrode system, and illustrates how surface pressure can be used to tune monolayer phases.

2-D phases↗