Juan Zuo

Bio: Juan Zuo is an academic researcher from Xiamen University of Technology. The author has contributed to research in topics: Electrode & Thin film. The author has an hindex of 13, co-authored 32 publications receiving 553 citations. Previous affiliations of Juan Zuo include Xiamen University & Max Planck Society.

Optimized porous rutile TiO2 nanorod arrays for enhancing the efficiency of dye-sensitized solar cells

Abstract: Highly ordered rutile TiO2 nanorod arrays (NRAs) are promising architectures in dye-sensitized solar cells (DSCs). However, the efficiency of DSCs based on such photoanodes is still relatively low, largely due to the limited internal surface area. Herein, we report that highly oriented rutile TiO2 NRAs with film thickness up to ∼30 μm was developed by a facile hydrothermal method. More importantly, an optimized porous rutile TiO2 NRAs with a large internal surface area was fabricated on the FTO (fluorine-doped tin oxide) substrate via a secondary hydrothermal treatment and when applied as the photoanodes in DSCs, a record efficiency of 7.91% was achieved.

Optical and electronic properties of native zinc oxide films on polycrystalline Zn

Abstract: The oxide layer spontaneously formed on zinc and an “electrochemically reduced” oxide has been characterised by a combination of X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE). The onset of the main electronic absorption, which is directly related to the bandgap, is extracted from the SE measurements. The SE results are compared with simulations on the basis of zinc and bulk zinc oxide optical constant data. Measurements in the ultraviolet and visible (UV–vis) spectral range show the presence of an absorption at ∼1.8 eV (680 nm) which is unaccounted for from the bulk data, and is likely to originate from intragap energy levels, implicating the presence of surface defects in the layers. Analysis of the Zn LMM Auger peaks in XPS data show the presence of Zn different from bulk zinc and bulk ZnO, attributed to excess Zn in the oxide films. Mid-infrared (IR) ellipsometry shows two peaks around 0.12 and 0.15 eV (1000 and 1200 cm−1), which strengthen the assumption of the presence of a locally distorted structure in the oxide layers. Electrochemically reduced samples show a much thinner oxide layer and higher Zn-doping concentration films than samples purely dipped in NaOH solution. Using a self-contained multiple sample SE analysis, estimates of the refractive index and absorption coefficient (i.e., the optical constants) of the oxide films are presented from 1.5–4.4 eV (280 to 810 nm).

First spectroscopic observation of peroxocarbonate/peroxodicarbonate in molten carbonate

Abstract: An active oxygen species in molten carbonate is the key to elucidate the complex mechanism of the cathode reaction in MCFC. However, under acidic condition of MCFC operation (P C O 2 > 1.01 x 10 4 Pa), the exact chemical state of the active oxygen species remains unclear and is a subject of continuous debates. In this work, we present the first experimental observation of peroxocarbonate/peroxodicarbonate species in acidic molten carbonate by using in-situ Raman spectroscopic technique. The results indicate that the predominant oxygen species (O 2 2-) in basic lithium-rich melts became unstable with the increase of acidity level in the melts and reacted with CO 2 to produce peroxocarbonate or peroxodicarbonate anion. In combination with the result of theoretical calculation, it is deduced that the peroxodicarbonate mechanism is the dominant feature in the cathode reaction path in MCFC.

A review of one-dimensional TiO2 nanostructured materials for environmental and energy applications

Abstract: One-dimensional TiO2 (1D TiO2) nanomaterials with unique structural and functional properties have been extensively used in various fields including photocatalytic degradation of pollutants, photocatalytic CO2 reduction into energy fuels, water splitting, solar cells, supercapacitors and lithium-ion batteries. In the past few decades, 1D TiO2 nanostructured materials with a well-controlled size and morphology have been designed and synthesized. Compared to 0D and 2D nanostructures, more attention has been paid to 1D TiO2 nanostructures due to their high aspect ratio, large specific surface area, and excellent electronic or ionic charge transport properties. In this review, we present the crystal structure of TiO2 and the latest development on the fabrication of 1D TiO2 nanostructured materials. Besides, we will look into some critical engineering strategies that give rise to the excellent properties of 1D TiO2 nanostructures such as improved enlargement of the surface area, light absorption and efficient separation of electrons/holes that benefit their potential applications. Moreover, their corresponding environmental and energy applications are described and discussed. With the fast development of the current economy and technology, more and more effort will be put into endowing TiO2-based materials with advanced functionalities and other promising applications.

TiO2 nanoparticles as functional building blocks.

Abstract: Lixia Sang,† Yixin Zhao,‡ and Clemens Burda* †Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing Municipality, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China ‡School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China Center for Chemical Dynamics and Nanomaterials Research, Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States

Effective nonmetal incorporation in black titania with enhanced solar energy utilization

Abstract: Nonmetal-doped black titania is achieved in a core–shell structure by a two-step synthesis. The nonmetal dopants in amorphous TiO2−x shells decrease e–h recombination centers, and more than 6.6 at.% N further improves solar energy absorption from 65% up to 85%. The photocatalytic H2 generation of the N-doped black titania is 15.0 mmol h−1 g−1 under 100 mW cm−2 of full-sunlight and 200 μmol h−1 g−1 under 90 mW cm−2 of visible-light irradiation, superior to TiO2−x and reported titania photocatalysis.