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Photoelectrochemical (PEC) technology for the conversion of solar energy into chemicals requires cost-effective photoelectrodes to efficiently and stably drive anodic and/or cathodic half-reactions to complete the overall reactions for storing solar energy in chemical bonds. The shared properties among semiconducting photoelectrodes and photovoltaic (PV) materials are light absorption, charge separation, and charge transfer. Earth-abundant silicon materials have been widely applied in the PV industry, and have demonstrated their efficiency as alternative photoabsorbers for photoelectrodes. Many efforts have been made to fabricate silicon photoelectrodes with enhanced performance, and significant progress has been achieved in recent years. Herein, recent developments in crystalline and thin-film silicon-based photoelectrodes (including amorphous, microcrystalline, and nanocrystalline silicon) immersed in aqueous solution for PEC hydrogen production from water splitting are summarized, as well as applications in PEC CO reduction and PEC regeneration of discharged species in redox flow batteries. Silicon is an ideal material for the cost-effective production of solar chemicals through PEC methods.

We investigate whether the adoption of International Financial Reporting Standards (IFRS) in 2005 by Australian firms has been associated with a loss of potentially useful information about intangible assets. We find that the negative association between the accuracy and dispersion of analysts' earnings forecasts and aggregate reported intangibles previously documented by Matolcsy and Wyatt (2006) becomes stronger subsequent to IFRS adoption, primarily for firms with high levels of underlying intangible assets. Our result is largely attributable to reported goodwill, rather than other intangible assets, suggesting that the impairment approach to goodwill valuation required by IFRS conveys more useful information than does the former straight-line amortization approach. When we investigate a sub-sample of firms that report lower intangibles under IFRS than under the prior Australian GAAP, we do find some evidence consistent with a loss of useful information relating to intangibles.

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A deposition process has been developed to fabricate a complete-monolayer Pt coating on a large-surface-area three-dimensional (3D) Ni foam substrate using a buffer layer (Ag or Au) strategy. The quartz crystal microbalance, current density analysis, cyclic voltammetry integration, and X-ray photoelectron spectroscopy results show that the monolayer deposition process accomplishes full coverage on the substrate and the deposition can be controlled to a single atomic layer thickness. To our knowledge, this is the first report on a complete-monolayer Pt coating on a 3D bulk substrate with complex fine structures; all prior literature reported on submonolayer or incomplete-monolayer coating. A thin underlayer of Ag or Au is found to be necessary to cover a very reactive Ni substrate to ensure complete-monolayer Pt coverage; otherwise, only an incomplete monolayer is formed. Moreover, the Pt monolayer is found to work as well as a thick Pt film for catalytic reactions. This development may pave a way to fabricating a high-activity Pt catalyst with minimal Pt usage.

Conductive biodegradable materials are of great interest for various biomedical applications, such as tissue repair and bioelectronics. They generally consist of multiple components, including biodegradable polymer/non-degradable conductive polymer/dopant, biodegradable conductive polymer/dopant or biodegradable polymer/non-degradable inorganic additives. The dopants or additives induce material instability that can be complex and possibly toxic. Material softness and elasticity are also highly expected for soft tissue repair and soft electronics. To address these concerns, we designed a unicomponent dopant-free conductive polyurethane elastomer (DCPU) by chemically linking biodegradable segments, conductive segments, and dopant molecules into one polymer chain. The DCPU films which had robust mechanical properties with high elasticity and conductivity can be degraded enzymatically and by hydrolysis. It exhibited great electrical stability in physiological environment with charge. Mouse 3T3 fibroblasts survived and proliferated on these films exhibiting good cytocompatibility. Polymer degradation products were non-toxic. DCPU could also be processed into a porous scaffold and in an in vivo subcutaneous implantation model, exhibited good tissue compatibility with extensive cell infiltration over 2 weeks. Such biodegradable DCPU with good flexibility and elasticity, processability, and electrical stability may find broad applications for tissue repair and soft/stretchable/wearable bioelectronics.

h i g h l i g h t sIdentifies rate-limiting material-level thermal conduction process in a Li-ion cell. Shows that interfacial thermal conduction between cathode and separator contributes 88% of total thermal resistance. Experimental data agrees with theoretical model on thermal contact resistance. Chemical bridging of this interface results in 4X reduction in thermal contact resistance. Results may contribute towards thermal safety of Li-ion cells. a b s t r a c tWhile Li-ion cells offer excellent electrochemical performance for several applications including electric vehicles, they also exhibit poor thermal transport characteristics, resulting in reduced performance, overheating and thermal runaway. Inadequate heat removal from Li-ion cells originates from poor thermal conductivity within the cell. This paper identifies the rate-limiting material-level process that dominates overall thermal conduction in a Li-ion cell. Results indicate that thermal characteristics of a Liion cell are largely dominated by heat transfer across the cathode-separator interface rather than heat transfer through the materials themselves. This interfacial thermal resistance contributes around 88% of total thermal resistance in the cell. Measured value of interfacial resistance is close to that obtained from theoretical models that account for weak adhesion and large acoustic mismatch between cathode and separator. Further, to address this problem, an amine-based chemical bridging of the interface is carried out. This is shown to result in in four-times lower interfacial thermal resistance without deterioration in electrochemical performance, thereby increasing effective thermal conductivity by three-fold. This improvement is expected to reduce peak temperature rise during operation by 60%. By identifying and addressing the material-level root cause of poor thermal transport in Li-ion cells, this work may contributes towards improved thermal performance of Li-ion cells.

Colossal solar energy conversion and storage studies using photoelectrochemical cells (PECs) have been undertaken in the past four decades; however, how to efficiently utilize solar energy despite the intermittent nature of sunlight still remains a challenge. In this paper, a WO 3 /TiO 2 hybrid photoelectrode was coupled with our newly developed all-vanadium photoelectrochemical cell (PEC) with the aim of implementing photoelectrochemical solar energy conversion and storage. Zeroresistance ammetry (ZRA) and electrochemical impedance spectroscopy (EIS) were employed to study the photoelectrochemical response of this system in the conversion and storage of solar energy both under illumination and in the dark. The preliminary results proved the feasibility of this approach to store/release solar energy, even under dark conditions and showed that hydrogen tungsten bronze was responsible for the storage and release of photogenerated electrons from the semiconductor. The results also indicated an important synergy between electron storage and the all-vanadium electrolytes, which potentially offers great reversibility, high-capacity electron storage, and significant improvement in the photocurrent. To better understand the observed photoelectrochemical and electrochemical impedance behavior of our system, a model that unfolds the WO 3 electron storage mechanism and photogenerated charge carrier pathways in the all-vanadium PEC is proposed.