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Hydrogen production through photocatalytic water splitting under visible-light irradiation is an appealing approach to generate clean and economical renewable energy resources. The key challenge in this field of research is to design and engineer cost-effective, green, and efficient photocatalysts. Recently, carbon-based photocatalysts have attracted huge interest for visible-light-driven hydrogen evolution reactions due to their high chemical stability, excellent electrical conductivity, and tunable surface characteristics. Here, a critical review on how various carbon-based materials such as carbon nitride, conjugated polymers, metal-organic frameworks, functionalized carbon quantum dots, and graphene derivatives emerged as next-generation photocatalysts for hydrogen production in the last five years is provided. We also highlight how the size-modulation and functionalization of nano-carbon-based materials with active species can lead to improved photocatalytic performance. Furthermore, the potential of carbon dots and graphene-derivatives as noble metal-free co-catalysts and solid electron mediators in hydrogen evolution reaction under visible light illumination is discussed. The review finally elaborates the research gap and future perspectives, paving the way for new research to develop efficient photocatalysts for hydrogen production.

Recent success in achieving highly stable Rb-containing organolead halide perovskites has indicated the possibility of incorporating small monovalent cations, which cannot fit in the lead-halide cage with an appropriate tolerance factor, into the perovskite lattice while maintaining a pure stable "black" phase. In this study, through a combined experimental and theoretical investigation by density functional theory (DFT) calculations on the incorporation of extrinsic alkali cations (Rb+, K+, Na+, and Li+) in perovskite materials, the size-dependent interstitial occupancy of these cations in the perovskite lattice is unambiguously revealed. Interestingly, DFT calculations predict the increased ion migration barriers in the lattice after the interstitial occupancy. To verify this prediction, ion migration behavior is characterized through hysteresis analysis of solar cells, electrical poling, temperature-dependent conductivity, and time-dependent photoluminescence measurements. The results collectively point to the suppression of ion migration after lattice interstitial occupancy by extrinsic alkali cations. The findings of this study provide new material design principles to manipulate the structural and ionic properties of multication perovskite materials.

In this study, copper flake was synthesized through wet ball milling the copper micro sphere, which was used as the filler of epoxy adhesives. The effect of ball milling time and dispersant on morphology of copper have investigated. The effect of ball milling with oleic acid as dispersant is more homogeneous than alcohol. The longer ball milling time, the higher proportion of Cu flake. When ball milling time comes to 2 hours, the thermal conductivity of copper adhesive filled with as-prepared Cu flake comes to threshold. Moreover, permissible voltage of copper adhesive filled with as-prepared Cu flake is reduced. This research provides an efficient way to synthesis Cu micro flake, which can used as the filler of thermal interface materials with high thermal conductivity for integrated circuit packaging application. © 2017 IEEE.

In this article, conductive nickel patterns were constructed on flexible substrates via selectively electroless deposition method, which including four procedures, namely KH550-modification, Ni2+ adsorption, selective Ni0-seeding and Ni-lines deposition. Herein, we use KH550 as a bridge for the catalyst and the surface of substrates, and Ni0 as catalyst to replace the traditional Pd catalyst. In this way, the conductive circuit can be prepared by adding method on the surface of the flexible substrate and suitable for large-scale production. © 2017 IEEE.

We used a facile method to prepare PdCu hollow nanocubes (HNCs) and nanospheres (HNSs) for electroless copper or nickel deposition by via redox reaction with the sacrificial templates of Cu2O. The electrocatalytic performance of PdCu HNSs is higher than PdCu HNCs through CV and EQCM tests. Also, PdCu HNSs was applied to electroless copper and nickel deposition, and find that the quite low concentration up to 1 mM and 2 mM of PdCu alloy for electroless copper and nickel deposition still has the good catalytic performance, respectively. © 2017 IEEE.

Mixed iodide-bromide organolead perovskites with a bandgap of 1.70-1.80 eV have great potential to boost the efficiency of current silicon solar cells by forming a perovskite-silicon tandem structure. Yet, the stability of the perovskites under various application conditions, and in particular combined light and heat stress, is not well studied. Here, FA(0.15)Cs(0.85)Pb(I0.73Br0.27)(3), with an optical bandgap of approximate to 1.72 eV, is used as a model system to investigate the thermal-photostability of wide-bandgap mixed halide perovskites. It is found that the concerted effect of heat and light can induce both phase segregation and decomposition in a pristine perovskite film. On the other hand, through a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions (e.g., film surface and grain boundaries) of the film can be well passivated, thus preventing the progression of decomposition or phase segregation in the film. Besides the stability improvement, the BA-modified perovskite solar cells also exhibit excellent photovoltaic performance, with the champion device reaching a power conversion efficiency of 18.1%, a stabilized power output efficiency of 17.1% and an open-circuit voltage (V-oc) of 1.24 V., Funding Agencies|Theme-based Research Scheme from the Research Grants Council of Hong Kong [T23-407/13-N]

Enormous efforts have been made towards the next generation of flexible, low-cost, environmentally benign printed electronics. In this regard, advanced materials for the printed conductive lines and interconnects are of significant importance. To improve efficiency and effectiveness, for several decades, conductive fillers have been filled into dispersants, which lead to the so-called electrically conductive composites (ECCs), which are a key material to the printed electronics varying from substituting the traditional solders to finding new applications in the blooming field of flexible printed electronics. ECCs in various formulations have converged in the current efforts to develop platforms with the desired specifications of electrical and thermal conductance, mechanical strength, and others. This platform is highly versatile and valuable for the emerging novel electronic devices, which emphasize tailoring processing conditions to cater to the key functional materials to optimize outcomes. The properties obtained can facilitate decisions about modifications to treatment. Noble metal fillers, such as silver flakes, have long been studied as active fillers for the ECCs. Owing to the recent progress in nanotechnology and surface modifications, many new avenues have opened for them. By taking advantage of the well-developed surface chemistry of these materials, researchers are enhancing their electrical conductivity, which is essential for broader applications. In recent years, the advances of ECCs have benefited the development of the applications of optoelectronics, e-papers, electromagnetic shielding, clinical diagnosis, radio frequency devices, etc. Despite the various advantages that they can offer over the traditional technologies, their limitations, e. g. low electrical conductivity, poor impact strength, increased contact resistance at elevated temperatures and humidity aging, have been considered as the major obstacles. In this feature article, we introduce

A scalable preparation method for high-quality silver nanowires (Ag NWs), which can be used as the electrical circuits for a broad spectrum of ultralow-cost, recyclable, foldable electronics, is presented. Paper-based radio-frequency identification (RFID) tags, light-emitting diode (LED) chip arrays, and 3D origami electrical devices are synthesized. The signal transmittance and biodecomposition of the RFID tags are investigated.