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The environmental toxicity of chemicals used in electroless plating process is often overlooked. In fact, the wastewater from the electroless plating process contains metal complexes, reducing agents and stabilizers that can create hazard to our environment. To address this concern, an additive-free electroless deposition process on graphene/Cu foil is proposed. The defect structure of graphene plays a pivotal role by acting as a reservoir for concentrating photoelectrons generated from ultra-thin cuprous oxide (Cu 2 O) located at the interface of graphene and Cu foil upon exposure to light irradiation. In the Cu ion solution, Cu ions were anchored on the defect sites and formed a Cu-C 4 structure with graphene. The Cu-C 4 sites accumulate abundant photoelectrons and trigger the reduction of Cu ions to form island-like growth of Cu, which immediately was oxidized to Cu 2 O, leaving only a small portion of metallic Cu. Concurrently, the presence of Cu ions induces the generation of additional defect sites on graphene, providing further growth sites for Cu deposition. This process continues until the entire graphene surface is covered by the deposited Cu 2 O. Ultimately, the deposition of metallic oxides with lower redox potential can be achieved. The proposed deposition mechanism assisted by irradiation of photocatalyst and defect structure of graphene material provides a truly environmentally friendly electroless plating process. By eliminating the need for additives and significantly reducing the environmental hazards associated with electroless plating, this method holds great promise for sustainable materials manufacturing. [Display omitted] • The additive-free electroless process ensures environmental sustainability. • In situ spectroscopy analysis revealed the deposition and growth of electroless Cu 2 O. • The formation of Cu–C bonds enhances the adhesion between Cu 2 O and graphene. [ABSTRACT FROM AUTHOR]

Abstract: The present study focuses on enhancing the efficiency of bifacial and back-illuminated dye-sensitized solar cells (DSCs) by incorporating SiO2 mesoporous layer on TiO2 electrode. The performance of DSCs is investigated by UV–visible spectroscopy, incident photon conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). It is observed that the current ratio of back- to front-DSC increases with the increase in the thickness of SiO2 layer, which in turn influences the incident light to dyed-TiO2 electrode, especially in the wavelength of 400–600 nm. The Ti foil based flexible small (0.28 cm2) and sub-module (5 cm × 10 cm) DSCs having this modification show high conversion efficiencies of 6.76 and 5.54% respectively under 100 mW cm−2 (AM 1.5). [Copyright &y& Elsevier]

Abstract: This study presents a baseband communication architecture in compliance with IEEE 802.15.4 physical layer specifications for body area network systems. The proposed architecture uses preambles for a correlation operation to detect the front end of symbols and then calculates the influence of a channel effect, for example, a carrier frequency offset (CFO). Using a cross-correlation and auto-correlation architecture to synchronize receivers, the data subject to the carrier frequency can be compensated with a coordinate rotation digital computer (CORDIC) structure. This study includes a system simulation for the purpose of signal compensation in both the transmitting and receiving ends. Results show that the proposed design correctly detects the CFO bias in radians, with a detection error less than 0.1%, indicating that the CFO is compensated. [Copyright &y& Elsevier]

Abstract: Tetrapod-like ZnO nanostructures prepared by dc plasma technology were used as photoelectrodes in dye-sensitized solar cells (DSSCs). Each of the tetrapod-like ZnO possesses four extended arms that offer improved electron transport properties. Tetrapod-like ZnO with short (S-ZnO) and long arms (L-ZnO) were synthesized by controlling the plasma gas flow and the input power. Between these two tetrapod-like ZnO nanopowders, the DSSCs using S-ZnO showed higher energy conversion efficiency than using L-ZnO. This is due to the resulting increase in dye adsorption and enhanced short-circuit current density, using S-ZnO. Electrochemical impedance spectroscopy (EIS) shows that the properties of electron transport of S-ZnO are superior to that of the L-ZnO. We investigated the effect of the redox electrolytes (I2) and the additives (LiI and TBP) on the performance of the DSSCs by intensity-modulated photovoltage spectroscopy and EIS. [ABSTRACT FROM AUTHOR]

Abstract: The ionic conductivities and performances of dye-sensitized solar cells (DSSCs) of gel polymer electrolytes (GPEs) prepared by in situ cross-link reaction with different cross-linkers were investigated. The poly(imidazole-co-butylmethacrylate)-based GPE containing the 1,2,4,5-tetrakis(bromomethyl)benzene (B4Br) cross-linker showed a higher ionic conductivity than that containing cross-linkers with a linear structure, due to the formation of micro-phase separation that resulted in an increase in ion transport paths in the GPE. Moreover, the co-adsorbent ((4-pyridylthio) acetic acid, PAA) co-adsorbed with N3 dye on the TiO2 electrode not only reduced dye aggregation, but also reacted with the cross-linkers in the GPE at the TiO2/GPE interface. A decrease in the charge transport resistance at the TiO2/GPE interface was noted after forming the gel; thus the value of J SC significantly increased from 7.72 to 10.00mAcm−2. In addition, in order to reduce the ionic diffusion resistance within the TiO2 electrode, incorporation of monodispersed PMMA in the TiO2 paste was considered. With the optimal weight ratio of PMMA/TiO2 (w/w=3.75), the TiO2 electrode exhibited larger pores (ca. 350nm) uniformly distributed after sintering at 500°C, and the ionic diffusion resistance within the TiO2 film could significantly be reduced. The cell conversion efficiency increased from 3.61% to 5.81% under illumination of 100mWcm−2, an improvement of ca. 55%. [Copyright &y& Elsevier]