bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Stand-Alone Photoreduction of Carbon Dioxide on Copper Oxide Nanowires Powered By WO3/Dye Dual Absorber
Authors: Nath Narayan Chandra Deb , Choi Seung Yo , Park Hyunwoong , Lee Jae-Joon 
Published: February 2020

A photoelectrochemical cell, composed of WO3/dye-sensitized solar cell (WO3/DSSC) and copper oxide (CuxO, where x = 1 and 2) nanowires as a dual absorber photoanode and cathode, respectively, is demonstrated as a stand-alone device for CO2 photoreduction to CO, H2 and formate. The single-absorber cell of a WO3 photoanode and CuxO nanowire cathode couple (WO3-CuxO) required the minimum overpotential of ~0.7 V to drive CO2 photoreduction. For the unassisted or stand-alone CO2 photoreduction, a DSSC was coupled to the WO3-CuxO system to construct a dual-absorber cell (WO3/DSSC-CuxO). In the dual-absorber cell, the long-wave band (λ > ca. 500 nm) passed through the semi-transparent WO3 film was absorbed by the dye-sensitized TiO2 electrode of DSSC. The WO3/DSSC-CuxO showed a potential gain of ~0.7 V, which resulted in the CO2 photoreduction successfully without supply of any external potential. In this stand-alone system, the primary CO2 conversion product is CO with solar-to-chemical energy efficiency of ~2.5% while H2 and formate are obtained with the energy efficiencies of 0.7% and 0.25%, respectively, in 5 h.
(Invited) SnS2 Nanostructure As a Highly Efficient Photocatalyst for CO2 Reduction to Solar Fuels
Authors: Chen Kuei-Hsien , Chen Li-Chyong , Shown Indrajit 
Published: February 2020

Photocatalytic CO2 reduction to solar fuels by artificial photosynthesis is an attractive and effective research area to solve the energy crisis as well as anthropogenic greenhouse emission problems from CO2 emission. In the past several years, many significant efforts have been applied to develop an efficient photocatalyst for the CO2 reduction to hydrocarbons. Among the entire reported photocatalyst several semiconductor materials together with carbonaceous hybrid materials GO, g-C3N4, TiO2/rGO, MoS2/rGO and Cu-GO have been reported as a promising photocatalyst for CO2 reduction to solar fuels conversion because of their comparatively low cost, low toxicity and photocorrosion resistance. However, wide bad gap semiconductor photocatalysts are not enough to use for practical application due to their limited visible light absorption. The promising prospect of these materials is far away from the commercial requirement due to the low quantum efficiency and lack of selectivity. Thus, it is a great challenge to develop a potential low-cost photocatalyst for a high CO2 reduction efficiency and produce desire solar fuel under visible light.
Since the discovery of graphene, two-dimensional (2D) layered transition metal dichalcogenides (TMDs) nanostructure are playing an important role in the various applications due to their crystal structure, a wide range of chemical compositions and optoelectronic properties. The wide range of electronic properties of TMD semiconductor materials is also promising for catalysis due to their strong correlation between electronic and catalytic properties. Last few years, several narrow band gap metal sulfides such as CdS, PbS, CdSe, MoS2 have been introduced as a photocatalyst or a co-catalyst together with another wide-band gap semiconductor for photocatalytic reaction under visible light. Although CdS and PbS contains sufficient potential characteristics as a photocatalyst, however, they explored less as a commercial photocatalyst due to the toxicity problem of Cd and Pb. Therefore, it's highly desirable to explore non toxic narrow bandgap metal sulfide for photocatalytic CO2 reduction. Among various, metal sulfides SnS2 is one of the narrow bandgap nontoxic semiconductor associate with dichalcogenide family. Recently, it has been attracted for its potential applications as a light absorber layer for desensitized solar cell, gas sensing, energy storage and conversion. SnS2 possesses CdI2 crystal structure, consisting sandwiched S-Sn-S layers bounded by weak van der Waals's interaction. The strong intra- and weak inter-layer inter-actions induce the high anisotropy of 2D SnS2. SnS2 is an n-type semiconductor with a narrow bandgap around 2.2-2.4 eV at room temperature, and high quantum yield, thus it shows several benefits to be a good photocatalyst behavior under visible light. The details photocatalytic performance, high quantum yield and selectivity of solar chemicals will be discussed.
Interface Engineering in Inorganic Hybrid Structures Towards Improved Photocatalysis
Authors: Xiong Yujie 
Published: February 2020

Designing new photocatalytic materials for improving photoconversion efficiency is a promising route to alleviate the steadily worsening environmental issues and energy crisis. Despite the invention of a large number of catalytic materials with well-defined structures, their overall efficiency in photocatalysis is still quite limited as the three key steps - light harvesting, charge generation and separation, and charge transfer to surface for redox reactions - have not been substantially improved. To improve each step in the complex process, there is a major trend to develop materials based on inorganic hybrid structures. In this case, interface engineering holds the promise for boosting the overall efficiency, given the key roles of interface structures in charge and energy transfer. In this talk, I will demonstrate several different approaches to designing inorganic hybrid structures with improved photocatalytic performance via interface engineering. The typical demonstrations include semiconductor-plasmonics systems for broad-spectrum light harvesting, metal-semiconductor interfaces for improved charge separation, semiconductor-MOF (metal-organic framework) configurations for activated surface reactions. It is anticipated that this series of works open a new window to rationally designing inorganic hybrid materials for photo-induced applications.

References:

(1) Bai, S.; Yang, L.; Wang, C.; Lin, Y.; Lu, J.; Jiang, J. and Xiong, Y.*, Angew. Chem. Int. Ed. 54, 14810-14814 (2015).
(2) Bai, S.; Jiang, J.; Zhang, Q. and Xiong, Y.*, Chem. Soc. Rev. 44, 2893-2939 (2015).
(3) Bai, S.; Li, X.; Kong, Q.; Long, R.; Wang, C.; Jiang, J. and Xiong, Y.*, Adv. Mater. 27, 3444-3452 (2015).
(4) Bai, S.; Ge, J.; Wang, L.; Gong, M.; Deng, M.; Kong, Q.; Song, L.; Jiang, J.;* Zhang, Q.;* Luo, Y.; Xie, Y. and Xiong, Y.*, Adv. Mater. 26, 5689-5695 (2014).
(5) Li, R.; Hu, J.; Deng, M.; Wang, H.; Wang, X.; Hu, Y.; Jiang, H. L.; Jiang, J.;* Zhang, Q.;* Xie, Y. and Xiong, Y.*, Adv. Mater. 26, 4783-4788 (2014).
Kinetic Study on Multielectron-Transfer Mechanism for Flake-Ball-Shaped Bismuth-Tungstate Photocatalyst
Authors: Hori Haruna , Takashima Mai , Takase Mai , Ohtani Bunsho 
Published: February 2020

It has been reported that flake ball (FB)-shaped particulate bismuth tungstate (Bi2WO6: BTO) particles prepared by hydrothermal method exhibit photocatalytic activity for oxidative decomposition of organic compounds comparable to that of a commercial titania photocatalyst, while the activity for methanol dehydrogenation is relatively low even with platinum-loaded ones [1]. These facts suggest that two (or four)-electron transfer to the surface-adsorbed oxygen (O2), requiring more anodic potential of electrons in photocatalyst particles, happens in FB-BTO, but no report on the evidence for the multielectron-transfer mechanism have been published. In this study, light-intensity dependence of the rate of acetic-acid decomposition was investigated to obtain kinetic evidence for the multielectron transfer.
FB-BTO, composed of particles of spherical assembly of BTO flakes, was prepared following the previous report [1]. As-prepared FB, its ball-milled samples (L and H) and their 773 K-calcined samples (500FB, 500L and 500H) were used for decomposition of acetic acid in aerobic aqueous suspensions under monochromatic photoirradiation by (A) a diffraction grating-type illuminator (Jasco CRM-FD; maximum 10 mW) or (B) a 365-nm UV-LED (maximum 320 mW).
Figure 1 shows order (n) of light-intensity dependences at four wavelengths (irradiation A) calculated by assuming; r = a × I
n (r: rate, a: constant and I: light intensity). Except for the samples L and H at 380 and 410 nm, BTO showed almost first-order light-intensity dependences at wavelengths between 320 and 410 nm. With the higher intensity irradiation (irradiation B), the order was decreased to ca. 0.5 order for FB and L as shown in Fig. 2. As has been reported previously, photocatalytic acetic-acid decomposition proceeds through radical-chain mechanism with an alkyl peroxy radical as a chain carrier when titania was used as a photocatalyst, and the order of light-intensity dependence was ca. 0.5 [2]. The above-mentioned first-order light-intensity dependence for the most BTO samples can be interpreted by combination of second-order dependence for the accumulation of two electrons to reduce O2 and 0.5-order dependence owing to the radical-chain mechanism. Difference in folding points of plots in Fig. 2 between FB and L was observed; a folding point for FB was appreciably lower than that of L. One of the possible reasons for this difference is that the probability of the second-photon absorption by one photon-absorbed FB particle within its lifetime is higher than that of L particle owing to larger volume of FB particles.
[1] F. Amano, K. Nogami, R. Abe, B. Ohtani, J. Phys. Chem. C. 112, 9320 (2008).
[2] T. Torimoto, Y. Aburakawa, Y. Kawahara, S. Ikeda, and B. Ohtani, Chem. Phys. Lett., 392, 220 (2004).

Figure 1
In Situ ATR-FTIR Investigation of the Effects of H2o and D2o Adsorption on the TiO2 Surface
Authors: Bahnemann Detlef Werner , Belhadj Hamza , Robertson Peter 
Published: February 2020

Surface hydroxyl groups on TiO2 play an important role for the photoinduced hydrophilicity as well as for photocatalytic reactions. Adsorbed species such as water and organic compounds are expected to affect the hydroxyl group behaviour on the TiO2 surface, however, their influences have to date not been clearly determined. Herein, a detailed investigation of H2O and D2O adsorption on the TiO2 surface (anatase) in the dark and under UV(A) irradiation is reported using ATR-FTIR spectroscopy. The adsorption and photocatalytic degradation of acetate on the TiO2 surface was also investigated in H2O and D2O. Adsorption of H2O with different ratios of D2O revealed an isotopic exchange reaction occurring on the surface of TiO2 in the dark. This isotopic exchange leads to a change in the behaviour of acetate with the intensity of the OH bending band between the carboxylate and the OH group at 900 cm-1 decreasing and ultimately disappearing in the dark.
Upon illumination with UV(A) light both, OH and OD groups are formed, which in turn increase the hydrophilicity of the TiO2 surface. The amount of OH and OD groups was found to increase in the presence of molecular oxygen. This increase is most likely caused by the photoadsorption of H2O and D2O due to photoinduced charge transfer processes [1]. On the other hand, the investigations show that during UV(A) irradiation the acetate molecules can adsorb again on the TiO2 surface which is explained by an increased surface area due to a de-aggregation of the particles agglomerates [2]. Based upon the observed correlation between the carboxylate and the OH and/or OD groups at neutral pH (pH ≈ pHzpc) it is obvious that acetate preferentially adsorbs on the positively charged anatase in a monodentate structure. As an in-situ technique, ATR-FTIR studies provide evidence of the adsorption behaviour of water and D2O on TiO2 surfaces thus yielding new insights into the mechanism of photoinduced hydrophilicity and of photocatalytic reactions.
Quinone Based Conducting Redox Polymers for Electric Energy Storage
Authors: Huang Hao , Karlsson Christoffer , Gogoll Adolf , Strømme Maria , Sjödin Martin 
Published: February 2020

Conducting redox polymers (CRP), consisting of conducing polymer (CP) and a redox active pendant group (PG) covalently linked to the CP backbone, have been suggested as electrode materials for secondary batteries. This type of material could provide an alternative to inorganic electrode materials and is favorable because of its renewability and sustainability (figure 1). Redox active organic compounds have previously been used as electrode materials for secondary batteries. However, due to the dissolution of many interesting compounds in common battery electrolytes, they suffer from poor recyclability and, in addition, the limited conductivity in these materials requires addition of substantial amounts of conductivity additives in the electrode formulation. By introducing a CP as backbone, not only the dissolution issue is solved, but also the conductivity will be greatly improved.
In our studies, we choose polypyrrole as CP, and p-benzoquinone as PG. Polypyrrole has been extensively studied and the electrochemistry and charge transport in this system is well understood. The corresponding knowledge of charge transport in CRPs is however to a large extent lacking. With the aid of temperature dependent in-situ conductivity measurements during the polymer doping process, mechanistic information on the charge transfer in quinone-based CRPs was investigated. Additionally, by varying the link between the two subunits the effect of linker on the performance of the materials was studied. With assistance of various in situ techniques, such as in situ conductivity measurement, in situ ATR-FTIR, EQCM, the interaction between the CP and PG was probed. It was found that the choice of linker has a substantial impact on the charge transport properties of the material. The insight gained from investigating the interaction between these two subunits will benefit further molecular variation of quinone-based electrode materials for secondary batteries.

Figure 1
Building Stable Radical Cations for Non-Aqueous Redox Flow Batteries
Authors: Zhang Lu , Shkrob Ilya A , Brogden Wes , Duan Wentao , Wei Xiaoliang , Assary Rajeev , Cheng Lei , Curtiss Larry , Brushett Fikile R. , Thompson Levi T 
Published: February 2020

E-mail: luzhang@anl.gov, shkrob@anl.gov
Abstract:
In advanced electrical grids of the future, electrochemically rechargeable fluids of high energy density could capture the power generated from intermittent sources like solar and wind. To meet this outstanding technological demand there is a need to understand the fundamental limits and interplay of electrochemical potential, stability, and solubility in low-weight redox-active molecules, among which, stability is the crucial factor for determining the real cycling performance. 1
,
2

The derivatives of 1,4-dimethoxybenzene are thus far the best performing catholyte molecules and have been intensively studied for non-aqueous redox flow batteries (NRFBs). However, most of these molecules have been found by trial and error, and the structural factors that determine durability of their radical cations (and even the nature of reactions controlling the life times of these radical cations) are insufficiently understood. In this report, an exploratory study focusing on the correlation between molecular symmetry and electrochemical stability was conducted. As shown in Fig 1, we examined a large selection of previously reported stable redox molecules3-5seeking for the root causes of the radical cation stability. By comparing their cycling performance, we observed that symmetric molecules are more likely to be stable than asymmetric ones. We rationalize this connection through the effect of symmetry on fragmentation (e.g., deprotonation) of a conformationally frozen radical cation. In asymmetric radical cations, the extra positive charge residing on the functional groups is unevenly distributed between them, causing more rapid fragmentation in the more positively charged groups. Following this observation, we have designed and synthesized several novel structures that are expected to be exceptionally stable redox molecules.

Figure 1. Molecular Structures for Redox Active compounds. The Symmetry Group and Estimated Dipole Moments (in Debye) are indicated in the Parentheses.

(1) Wei, X.; Xu, W.; Huang, J.; Zhang, L.; Walter, E.; Lawrence , C.; Vijayakumar, M.; Henderson, W. A.; Liu, T.; Cosimbescu, L.; Li, B.; Sprenkle, V.; Wang, W. Angewandte Chemie International Edition
2015, 54, 8684.
(2) Wei, X.; Cosimbescu, L.; Xu, W.; Hu, J. Z.; Vijayakumar, M.; Feng, J.; Hu, M. Y.; Deng, X.; Xiao, J.; Liu, J.; Sprenkle, V.; Wang, W. Adv. Energy Mater.
2015, 5, 10.1002/aenm.201570002.
(3) Huang, J.; Cheng, L.; Assary, R. S.; Wang, P.; Xue, Z.; Burrell, A. K.; Curtiss, L. A.; Zhang, L. Adv. Energy Mater.
2015, 5, 1401782.
(4) Zhang, L.; Zhang, Z.; Redfern, P. C.; Curtiss, L. A.; Amine, K. Energy & Environ. Sci.
2012, 5, 8204.
(5) Zhang, Z.; Zhang, L.; Schlueter, J. A.; Redfern, P. C.; Curtiss, L.; Amine, K. J. Power Sources
2010, 195, 4957.

Figure 1
The Gamma-V2O5 phase: A High Voltage Cathode Material for Sodium-Ion Batteries
Authors: Safrany-Renard Marianne , Baddour-Hadjean Rita , Muller-Bouvet Diane , Pereira-Ramos Jean-Pierre 
Published: February 2020

The growing interest in the Na-ion batteries is justified by cost and availability of sodium resources combined with an insertion chemistry close to the lithium one. While α-V2O5 was one of the first example of Li intercalation compounds only a few works report Na insertion into that layered host lattice. We recently reported sodium insertion into the so called α-V2O5 with a capacity of 120 mAh/g at a low voltage of 1.6V [1]. In this work a new sodium insertion compound is prepared by the chemical oxidation of the γ-LiV2O5 using NO2BF4 as oxidizing agent. One sodium ion per mole of γ’-V2O5 can be reversibly inserted at a remarkably high potential of 3.3V against 1.6V in the usual α-V2O5 (figure 1). The γ’-V2O5 electrode can deliver a reversible and stable capacity of 145 mAh/g at C/60 and 50°C and 125 mAh/g at C/20. An excellent capacity retention is also demonstrated at RT with 80 mAh/g recovered after 100 cycles at C/20. A two phases mechanism involving the γ’-V2O5 / γ-NaV2O5 system is evidenced from XRD and Raman spectroscopy experiments. The structural features of the fully sodiated γ-NaV2O5 phase with an usual expansion of the interlayer spacing (+2Å/compared to γ’-V2O5) are solved. These results reveal that the γ’-V2O5constitutes a new competitive cathode material for the reversible intercalation of sodium ions.
Reference
[1] D. Muller-Bouvet, R. Baddour-Hadjean, M. Tanabe, L.T.N. Huynh, M.L.P. Le, J.P. Pereira-Ramos
Electrochemically formed α’-NaV2O5 : A new sodium intercalation compound

Electrochimica Acta2015, Vol. 176 (2015) 586-593
doi : 10.1016/j.electacta.2015.07.030

Figure 1
(Invited) Li-S Battery and Beyond Systems: Composite Cathodes, Li Anodes and Prospects
Authors: Guo Yu-Guo 
Published: February 2020

Rechargeable Li metal batteries including Li-S, and Li-O2 batteries have become attractive candidates for the next-generation rechargeable electrochemical energy storage systems with high-energy densities because of their high theoretical energy densities and cost effectiveness. Here, we report our recent progress in Li-S and Li-Se batteries including S-C and Se-C composite cathodes, Li metal anodes, and the electrode/electrolyte interfaces. In contrast to the extensive studies of the electrochemical behavior of conventional cyclic S8 molecules in Li-S batteries, there has been hardly any investigation of the electrochemistry of S chains. Here we use S chains encapsulated in single- and double-walled carbon nanotubes as a model system and report the electrochemical behavior of 1D S chains in Li-S batteries. In addition, rational design of S-C composite cathodes with high sulfur loading and remarkable electrochemical properties will also be reported. On lithium metal anode we show that a 3D current collector with a submicron skeleton and high electroactive surface area can significantly improve the electrochemical deposition behavior of Li. Li anode is accommodated in the 3D structure without uncontrollable Li dendrites. We also demonstrate that an artiﬁcial SEI layer with high Young’s modulus can restrain Li dendrite growth and reduce the side reaction between Li metal and the organic electrolyte.
References:

C.-P. Yang, Y.-X. Yin, S.-F. Zhang, N.-W. Li, Y.-G. Guo,
Nat. Commun.
, 2015, 6, 8058

N.-W. Li, Y.-X. Yin, C.-P. Yang, Y.-G. Guo,
Adv. Mater.
, 2016, 28, 1853-1858

S. Xin, L. Gu , N.-H. Zhao, Y.-X. Yin, L.-J. Zhou , Y.-G. Guo, L.-J. Wan,
J. Am. Chem. Soc.
, 2012, 134, 18510-18513

C.-P. Yang, Y.-X. Yin, Y.-G. Guo, L.-J. Wan,
J. Am. Chem. Soc.
, 2015, 137, 2215–2218

Y.-X. Yin, S. Xin, Y.-G. Guo, L.-J. Wan,
Angew. Chem. Int. Ed.
, 2013, 52, 13186-13200

C.-P. Yang, S. Xin, Y.-X. Yin, H. Ye, J. Zhang, Y.-G. Guo,
Angew. Chem. Int. Ed.
, 2013, 52, 8363-8367

W.-C. Du, Y.-X. Yin, X.-X. Zeng, J.-L. Shi, S.-F. Zhang, L.-J. Wan, Y.-G. Guo,
ACS Appl. Mater. Interfaces,

2016, 8, 3584−3590

C.-P. Yang, Y.-X. Yin, H. Ye, K.-C. Jiang, J. Zhang, Y.-G. Guo,
ACS Appl. Mater. Interfaces,

2014, 6, 8789-8795

H. Ye, Y.-X. Yin, Y.-G. Guo,
Electrochim. Acta
, 2015, 185, 62–68

C.-P. Yang, Y.-X. Yin, Y.-G. Guo,
J. Phys. Chem. Lett.
, 2015, 6, 256-266
Nmr's Perspective of Speciation Process in Lithium Sulfur Batteries
Authors: Wang Hao , Key Baris , Sa Niya , He Meinan , Vaughey John T. , Nazar Linda F , Balasubramanian Mahalingam , Gallagher Kevin G. 
Published: February 2020

Lithium sulfur (Li-S) battery is a promising alternative technology of lithium ion batteries. However, due to the complicity of the chemistry in Li-S batteries, the mechanism is not well understood. In addition, the co-existence of soluble species and insoluble species limits the application of other characterization techniques. The sensitivity and element selectivity make NMR spectroscopy a powerful tool to study the changes in local chemical environment and speciation process in Li-S batteries. In this study, in situ
7Li NMR spectroscopy was employed where plastic pouch cells were assembled and cycled in the magnet while NMR spectra were acquired simultaneously. Method to quantitatively study entire lithium inventory in a Li-S battery is developed and implemented, and the cell design is optimized for electrochemical performance and spectroscopic resolution. This methodology can be readily extended to Li-S batteries with other electrolytes where the speciation process can be tracked and analyzed. The development of electrolyte will also benefit greatly from the detailed understanding of the Li-S battery speciation process as well as the additive development.
[1] See, et. al., J. Am. Chem. Soc., 2014, 136 (46), pp 16368–16377
[2] Xiao, et. al., Nano Lett., 2015, 15, 3309-3316