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The g -C 3 N 4 is synthesized by directly heating the acetic acid treatment melamine. A combination of XRD, SEM, TEM, PL and UV–vis are utilized to characterize the composition, morphology and optical properties of g -C 3 N 4 . This method synthesized g -C 3 N 4 shows smaller particles and some holes which high up the photocatalytic activity compared with the bulk g -C 3 N 4 . [ABSTRACT FROM AUTHOR]

The perovskite CH 3 NH 3 PbBr 3 films were synthesized by mixing the solution of CH 3 NH 3 Br and PbBr 2 . The effect of modulating the molar ratios of organic to inorganic content on morphology and optical properties of CH 3 NH 3 PbBr 3 was explored. The optical band gap of CH 3 NH 3 PbBr 3 can be tuned from visible to infrared regions by changing the CH 3 NH 3 Br content. It was also found that the photoluminescence (PL) emission intensity decreases and the emission colors of these films change from bright green to dark in a darkroom, with decreasing molar ratio. The electronic states of C, N, Br, Pb in CH 3 NH 3 PbBr 3 films were investigated to clarify the tunability of the optical band gap and PL intensity. [ABSTRACT FROM AUTHOR]

• The nanoparticles may lead to damage of substrate under the action of laser plasma. • The damage probability of the substrate is closely related to the size of particles. • The break-up and melting of nanoparticles can increase the difficulty of removal. With technological advancement, plasma shockwaves have become widely used as a novel cleaning method to remove nanoparticles. However, insufficient research has been conducted on their cleaning mechanism and application conditions, and the yield strength of substrates has been directly used as their damage threshold. we find that this definition is inaccurate. We treat clean and nanoparticle-coated silicon substrates with a laser-induced plasma shockwave to explore the effects of the presence of nanoparticles on the substrate during cleaning. We have confirmed the effect of nanoparticles on the substrate by simulating the mechanism of temperature and stress propagation between the particles and the substrate. This is because the yield strength of the substrate is greatly reduced by the increase of temperature under the action of shock wave. At the same time, the stress transferred by particles to the substrate increases, resulting in local high-pressure area and pit formation. Moreover, this study finds that the presence of nanoparticles increases the probability of damage to the substrate by an approximate factor of two. And the dependence of the damage threshold of the substrate on the size of the nanoparticles is demonstrated. [ABSTRACT FROM AUTHOR]

The microscale glass beads were added into poly (ε-caprolactone)/multi-wall carbon nanotube composites to achieve high performance microwave shielding property via balancing absorption in conductive domains and multiple scattering at interfaces. • Microwave shielding of the composites was improved by microscale glass beads. • Microscale glass beads induced multiple interfaces for microwave scattering. • Microwave shielding was enhanced by multiple scattering at interfaces. • Microwave shielding was related to the absorption in conductive domains. • Excellent scattering and absorption exhibits excellent shielding effectiveness. In this work, multiple interfaces for scattering electromagnetic waves were constructed in the poly(ε-caprolactone)/multi-wall carbon nanotube composites (PCLNT) by adding microscale glass beads (μ-GB). The high-performance microwave attenuation of the PCLNT/μ-GB composites was found to be dependent on the microwave absorption in conductive domains and the multiple scattering at interfaces. The multiple scattering was enhanced by increasing the content of μ-GBs. However, the conductive domains were separated by adding more μ-GBs, which led to reduce the absorption. Therefore, the electromagnetic interference (EMI) shielding effectiveness (SE) of the samples increased by adding low μ-GB loadings and decreased by adding high μ-GBs loadings. Fortunately, the absorption of microwaves was enhanced by increasing the conductivity (MWCNT loading) in the conductive domains, which compensated the reduction from decreasing thickness of the conductive domains among μ-GBs. The EMI SE of the PCLNT/μ-GB composites with 50 wt% μ-GBs enhanced from ~34 to ~44 dB by increasing MWCNT loadings in PCL phase from 3.0 to 6.0 wt%. Therefore, the PCLNT/μ-GB composites with high-performance microwave shielding property could be achieved by balancing the absorption in conductive domains among μ-GBs and the multiple scattering at interfaces. [ABSTRACT FROM AUTHOR]

A simple hydrothermal route is designed to decorate NiCo 2 S 4 nanoparticles on the surface of N-doped carbon nanotubes to form a coaxial composite (NiCo 2 S 4 @NCNT). Inherited the high electrical conductivity from the NCNT and high capacitive performance of NiCo 2 S 4 , the optimized NiCo 2 S 4 @NCNT composite could significantly reduce the contact resistance and effectively increase the transfer rate of ion and electron and thus benefit for its electrochemical performance enhancement. When employed as a battery-type supercapacitor electrode, the NiCo 2 S 4 @NCNT composite exhibits a high capacitance up to 783.5 C g −1 at 1 A g −1 and as well as rate performance (74.6% retention with the current density increases from 1 to 50 A g −1 ). Coupled with activated carbon (AC) negative electrode, the as-assembled hydride supercapacitor delivers a maximum energy density of 49.75 Wh kg −1 at a power density of 774.65 W kg −1 , as well as 88.9% capacitance retained after 3000 cycles at a current density of 10 A g −1 . These above results demonstrate the enormous potential of NiCo 2 S 4 @NCNT in the development of hybrid supercapacitors. [ABSTRACT FROM AUTHOR]

A series of natural-biogum-deprived carbon composites Si@GAC, Si@GGC and Si@XGC anode materials have been constructed, among which Si@GAC shows the best initial Coulombic efficiency (ICE) resulting from conformal carbon layer containing heteroatoms and covalent interactions with Si core. Based on this result, artificial graphite (AGr) and natural graphite (NGr) are added during the preparation process of Si@GAC to further elevate ICE and cycling stability. This strategy successfully realizes simultaneous and effective improvement of ICE and cycling performance, which could ultimately provide inspiration for high-performance silicon-based anodes. [Display omitted] • Si@C@Graphite materials with enhanced ICE and cycling stability are synthesized. • N, O render dominant capacitive Li+ storage mechanism and faster Li+ transfer. • Artificial graphite better enhances overall electrochemical performance. • Covalently-attached C layer with heteroatoms is conducive to cycling stability. Regarded as one of the most prospective anode materials for lithium-ion batteries (LIBs), silicon (Si) exhibits the highest theoretical capacity (4200 mAh g−1) among various anode materials while generally suffers from huge volume change, resultant rapid capacity fading and low initial Coulombic efficiency (ICE). Here, the ICE and cycling performance of Si-based anode have been simultaneously improved through preparing Si@C@Graphite materials where the conformal carbon modifiers derived from natural biopolymer binders covalently attached to Si particles could enhance the cycling stability, among which GA-derived carbon layer with N, O heteroatoms could best ameliorate the Li+ transport kinetics and thereby rendering superior electrochemical properties, while artificial graphite (AGr) could significantly promote the overall ICE and more effectively elevate the reversible capacity. An excellent ICE (86.4%), a prominent rate performance (1240.6 mAh g−1 at 2000 mA g−1) and a promoted cycling stability (1320.5 mAh g−1 at 800 mA g−1 after 100 cycles) could be presented by Si@GAC@AGr anode. This research provides an effective strategy of simultaneously improving ICE and cycling performance of Si-based anodes and inspires rational design of high-energy–density LIB anodes. [ABSTRACT FROM AUTHOR]

• Carbon-coated SnS nanosheets and reduced graphene oxide composites are designed and synthesized. • Dual-carbon modification enhances the rate performance of SnS. • Potassiation stage adjustment results in stable cycling performance. Potassium ion batteries (PIBs) have attracted lots of attention due to its abundant resources. Exploring capable anode materials becomes one of the critical issues to achieve high-performance PIBs. Herein, carbon-coated SnS nanosheets and reduced graphene oxide (SnS@C/rGO) composite are designed and synthesized by a solvothermal reaction and heat treatment. The strategy of double carbon modification enhances the rate performance of SnS. Meanwhile, the cycling stability of SnS@C/rGO can be further improved by optimizing the voltage window, which can achieve the potassiation stage adjustment. K ions storage mechanism of SnS@C/rGO is investigated under different voltage windows. The deep alloying reaction occurs under low potential and is harmful to cycling performance. Moreover, the electrochemical kinetics of K ions storage is investigated by quantitative kinetics analysis. This work highlights the important effect of dual-carbon modification and adjusting the potassiation stage on the K ion storage. [ABSTRACT FROM AUTHOR]

• NiNb 2 O 6 @NC-2 hollow nanoparticles is used as rate capability anode for LICs. • The NiNb 2 O 6 @NC-2 exhibits a high specific capacity of 435.8 mAh g−1 at 50 mA g−1. • NiNb 2 O 6 decomposes into Ni metal and Li x Nb 2 O 6 in the 1st charge/discharge process. • The NiNb 2 O 6 @NC//AC LICs has a maximum energy density of 123.9 Wh kg−1. Searching for anode materials with fast Li+ intercalation kinetics to mitigate the dynamic imbalance with the rapid capacitive cathode is the fundamental strategy to achieve high energy-power density of Li-ion capacitors (LICs). Hence, NiNb 2 O 6 hollow nanoparticles are first synthesized by hydrothermal method and then sealed with a protective N-doped carbon shell to achieve the target NiNb 2 O 6 @NC composite. As the anode of LICs, the NiNb 2 O 6 @NC sample exhibits a high capacity of 435.8 mAh g−1 at 50 mA g−1 and excellent rate performance of 47.8% capacity retention with the current density increased to 2 A g−1. The lithium storage mechanism of NiNb 2 O 6 is proposed as a combined conversion reaction and an intercalation reaction, which the NiNb 2 O 6 decomposes into Ni metal and Li x Nb 2 O 5 during the 1st discharge/charge process. The irreversible Ni would not contribute to the reversible capacity and will improve the electric conductivity for fast transport of electrons and the Li x Nb 2 O 5 will act as the host for lithium ions by means of the intercalation mechanism. Furthermore, the assembled NiNb 2 O 6 @NC//activated carbon LICs exhibit a maximum energy density of 123.9 Wh kg−1 and the capacity retention reaches 86.1% after 5000 cycles. The superior electrochemical performances indicate that the rationally-designed NiNb 2 O 6 @NC is expected to be a potential anode material for LICs. [ABSTRACT FROM AUTHOR]

• The human hair with high elasticity capable can serve as a promising flexible supporter for the electrode. • The reduced graphene oxide nanosheets can effectively improve the electrical conductivity of the electrode. • The Ni(OH) 2 nanoribbon-intercalated rGO nanosheets shows an interconnected porous structure. • The solid-state flexible supercapacitor delivers high energy density and good cycling stability. The demands for wearable energy storage devices keep growing and novel flexible electrode materials and facile prepared methods for these devices are crucial and attractive. In this work, human hair fiber is employed as the flexible fiber-based material due to the high utilization values of low cost, controllable length and high elasticity capable. Herein, an effective and hazard-free microwave-assisted method is reported to develop superelastic reduced graphene oxide coating human hair (rGO@Hh) to achieve conductive and high-strength fibrous electrode. With the braided rGO@Hh fibers, nickel hydroxide nanoribbon-intercalated rGO nanosheets (Ni(OH) 2 /rGO@Hh) are further prepared through microwave radiation treatment, which shows an interconnected porous structure with outstanding electrochemical performances of high specific capacitance (316 F g−1 at 1 A g−1) and good cycling performance. Moreover, a solid-state fiber-based asymmetric supercapacitor (FASC) is assembled with rGO@Hh fibers and Ni(OH) 2 /rGO@Hh fibers as negative and positive electrodes, which demonstrates a high energy of 27.6 Wh kg−1 and a power density of 699 W kg−1, respectively. The FASC also can be further used for numerous electronic products, presenting its prospect for portable wearable devices with high tensile strength and excellent performances. [ABSTRACT FROM AUTHOR]