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Antimony-based materials have been considered as highly competitive anodes for sodium-ion batteries (SIBs) because of their high theoretical capacity. However, the poor rate capability and fast capacity fading, originating from sluggish kinetics and volume expansion, greatly restrict their practical application. To address the above issues, an effective spraying method and one-step partial reduction process were utilized to synthesize Sb2O3@Sb nanoparticle impregnated in N-doped carbon microcages (Sb2O3@Sb@NC) offering extraordinary sodium storage capabilities and delivering an ultra-high rate performance of 175.1 mA h g−1 at 20 A g−1 and a superior capacity retention of 245.2 mA h g−1 after 10 000 cycles under 10 A g−1 for SIBs. Such unprecedented electrochemical properties of the Sb2O3@Sb@NC electrode can be ascribed to the comprehensive characteristics derived from multi-scale structural engineering: the fast electrochemical kinetics and tight packing of Sb2O3@Sb nanoparticles with carbon sheets, the strong Na+ adsorption ability of Sb2O3@Sb@NC enhanced by the synergistic effect of heterostructures and N-doping, the structural integrity strengthened by a robust interface bond of Sb–O–C, and the improved pseudocapacitive contribution. These distinct features enable the Sb2O3@Sb@NC anode to be a potential candidate for large-scale sodium ion storage.

Bismuth-antimony alloy is considered as a promising potassium ion battery anode because of its combination of the high theoretical capacity of antimony and the excellent rate capacity of bismuth. However, the large volume change and sluggish reaction kinetic upon cycling have triggered severe capacity fading and poor rate performance. Herein, a nanoconfined BiSb in tremella-like carbon microspheres (BiSb@TCS) are delicately designed to address these issues. As-prepared BiSb@TCS renders an outstanding potassium-storage performance with a reversible capacity of 181 mAh g-1 after ultralong 5700 cycles at a current density of 2 A g-1 , and an excellent rate capacity of 119.3 mAh g-1 at 6 A g-1 . Such a superior performance can be ascribed to the delicate microstructure. The self-assembled carbon microspheres can strengthen integral structure and effectively accommodate the volume expansion of BiSb nanoparticles, and 2D carbon nanowalls in carbon microspheres can provide fast ion/electron diffusion dynamic. Theoretical calculation also suggests a thermodynamic feasibility of alloyed BiSb nanoparticles for storing potassium ion. Such a work shows that BiSb@TCS possesses a great potential to be a high-performance anode of potassium ion batteries. The rational designing of multiscaled structure would be instructive to the exploitation of other energy-storage materials.

Potassium-ion energy-storage devices have established themselves as the most important candidates for next-generation energy-storage devices in the coming future. Recently, inorganic electrode materials have riveted ever-increasing interest due to large theoretical capacity, rich sources, low price and environmental friendly advantages. However, the electrode materials of potassium-containing devices have been suffering low theoretical capacity, poor rate performance and short lifespan due to integration effects of seriously electrochemical pulverization and slow kinetics. In this timely review, we will focus on the latest progress of potassium ion energy storage devices based on beyond-carbon materials, referring to the synthesis of materials and the construction of microstructure, material component-oriented electrochemical performance, energy storage mechanism discussion, newfangled device assembly and key components. The key materials and novel theories are reviewed, and some personal viewpoints have been proposed, targeting providing some inductive opinions.

The rapid development of organic-inorganic hybrid perovskite solar cells has recently attracted the worldwide attention because their power conversion efficiency has risen from 4% to higher than 20% within just six years. It is well known that the perovskite materials with APbI3 crystal structure have a 3D framework of corner-sharing PbI6 octahedra, in which each Pb atom bonds with six I atoms, and the A cations fill in the octahedral interstices. At present, a lot of researches have focused on the synthesis and doping modification of perovskite materials. However, it is hard to detect directly the weak interactions between A cations and PbI6 skeleton in the APbI3 crystal structure through experiments, which have effect on the structural stability and electronic properties. To provide a full understanding of the interplay among size, structure, and organic/inorganic interactions, the stability, electronic structures and optical properties of APbI3 (A denotes Cs+, NH4+, MA+, FA+) were investigated by the plane-wave ultra soft pseudo potentials. Two dispersion corrections were taken into account in the weak interactions between A cations and PbI6 skeleton in the APbI3 crystal structure, respectively. The results show that the type and size of cations affect the distortion of PbI framework, indicating that the larger the radius of the A cation is, the stronger the interaction between the A cation and the PbI framework is. Further, it is identified that after geometry relaxation, the orientation of A cations (A denotes NH4+, MA+, FA+) is easy to change, and the PbI frameworks present structural distortion. CsPbI3 is more stable energetically than other three kinds of perovskite materials. For the PbI6 octahedra, the large dipole moments of 0.23D and 0.32D for the generalized-gradient approximation method or 0.28D and 0.29D for the local-density approximation method are also present in MAPbI3 and FAPbI3, respectively. In addition, the energy band structures, which affect the generation and migration of photon-generated carriers and optical properties, will alter with the structural distortion of PbI frameworks. By analyzing the energy band structures and corresponding density of states, we find that four systems have similar band structures near the Fermi energy, namely, the top of valance band is mainly contributed by I 5p orbitals, while the bottom of conduction band is dominated by Pb 6p orbitals and partly contributed by I 5p orbitals. A little difference of their electronic structures and optical absorption spectra originates from the distortion of PbI6 octahedra in APbI3 crystal structures. It is noted that the contribution of the ions Cs+ and FA+ on the top of valance band is slightly larger than that of the ions NH4+ and MA+. Compared with other three kinds of perovskite materials, CsPbI3 presents the narrowest direct band gap, the lowest effective carrier mass and excellent visible-light and infrared absorption. The results may provide some theoretical guidance for further research on perovskite materials in the application of solar cells.

To improve the efficiency of water-splitting, a key way is to select suitable semiconductor or design semiconductor based heterostructure to enhance charge separation of photogenerated h+-e- pairs. It is possible for a two-dimensional (2D) heterostructure to show more efficient charge separation and transfer in a short transport time and distance. Among numerous heteromaterials, the 2D layered MoS2 has become a very valuable material in photocatalysis-driven field due to the appropriate electronic structure, peculiar thermal and chemical stability, and low-cost preparation. To couple with MoS2, layered graphene will be an ideal candidate due to extremely high carrier mobility, large surface area, and good lattice match with MoS2. At present, a lot of researches focus on the synthesis and modification of MoS2/graphene heterostructure. However, it is hard to detect directly the weak interaction between MoS2 and graphene through the experiment. Here, an effective structural coupling approach is described to modify the photoelectrochemical properties of MoS2 sheet by using the stacking interaction with graphene, and the corresponding effects of interface cohesive interaction on the charge redistribution and the band edge of MoS2/graphene heterostructure are investigated by using the planewave ultrasoft pseudopotentials in detail. Three dispersion corrections take into account the weak interactions between MoS2 and graphene, resulting in an equilibrium layer distance d of about 0.34 nm for the MoS2/graphene heterostructure. The results indicate that the lattice mismatch between monolayer MoS2 and graphene is low in contact and a van der Waals interaction forms in interface. Further, it is identified by analyzing the energy band structures and the threedimensional charge density difference that in the MoS2 layer in interface there appears an obvious electron accumulation, which presents a new n-type semiconductor for MoS2 and a p-type graphene with a small band gap ( 0.1 eV). In addition, Mo 4d electrons in the upper valence band can be excited to the conduction band under irradiation. And the orbital hybridization between Mo 4d and S 3p will cause photogenerated electrons to transfer easily from the internal Mo atoms to the external S atoms. The build-in internal electric field from graphene to MoS2 will facilitate the transfer and separation of photogenerated charge carriers after equilibrium of the MoS2/graphene interface. It is identified that the hybridization between the two components induces a decrease of band gap and then an increase of optical absorption of MoS2 in visible-light region. It is noted that their energy levels are adjusted with the shift of their Fermi levels based on our calculated work function. The results show that the Fermi level of monolayer MoS2 is located under the conduction band and more positive than that of graphene. After the equilibrium of the MoS2/graphene interface, the Fermi level shifts toward the negative direction for MoS2 and the positive direction for graphene, respectively, until they are equal. At this time, the conduction band and valence band of MoS2 are pulled to the negative direction a little, and then form a slightly upward band bending close to the interface between MoS2 and graphene. Combining the decrease of the band gap of MoS2 in heterostructure, the potential of the conduction band minimum of MoS2 in heterostructure will increase to -0.31 eV, which enhances its reduction capacity. A detailed understanding of the microcosmic mechanisms of interface interaction and charge transfer in this system can be helpful in fabricating 2D heterostructure photocatalysts.

This study aimed to assess the effect of various power settings of the potassium-titanyl-phosphate (KTP) green laser on the vaporization of biological tissue under water and its potential and feasibility to treat patients with benign prostatic hyperplasia (BPH) and other urological disorders.BPH, ureteral strictures, and bladder tumors are common urological diseases in elderly men. KTP green laser vaporization is a safe and effective procedure used to treat urological diseases.Porcine muscles were vaporized at different power levels (7.5-57 W) under water by the KTP green laser system. Fresh canine prostate tissues were also vaporized with a 43-W green laser. Laser vaporization of human urological tissue was performed clinically.The porcine muscles were vaporized under water for 10 sec. Increasing laser power appeared to increase the depth and diameter of vaporization while maintaining or decreasing the depth of necrosis. With the 60-W KTP green laser system, laser prostatectomy was performed on 15 patients with BPH. This green laser system was also used to treat 12 strictures and 9 superficial bladder tumors. All patients received spinal anesthesia, and isotonic saline at room temperature was used as irrigation solution. Postoperative insertion of an indwelling catheter was mandatory.With increasing laser power settings, the vaporization depth and width increased significantly, but the depth of necrosis declined slightly. Green laser vaporization is a treatment method that can be adopted to treat patients with BPH, urethral stricture, and other urological diseases safely and effectively.

An effective compensated codoping approach is described to modify the photoelectrochemical properties of anatase TiO2 by doping with nonmetals (N or C) and transition metals (V or Cr) impurities. Here, compensated codoped TiO2 systems are constructed with different dopant species and sources, and then their dopant formation energies and electronic structures are performed to study the stability and visible-light photoactivity by first-principles plane-wave ultrasoft pseudopotential calculations, respectively. The calculated results demonstrate that the codoping with transition metals facilitates the enhancement of the concentration of p-type dopants (N and C) in a host lattice. Especially, compensated codoping not only reduces the energy gap, to enhance the optical absorption, and eliminate the local trapping, to improve carrier mobility and conversion efficiency, but it also keeps the oxidation-reduction potential of the conduction band edge. These results are conducive to the understanding of the synergistic mechanism of the photocatalytic activity of TiO2 that is enhanced by codoping.

The micro-explosion during Ho:YAG laser lithotripsy may cause calculus fragmentation and migration. It plays an important role to the surgery. A numerical simulation of the micro-explosion during Ho:YAG laser lithotripsy has been developed. The explosion problem in water environment was solved by the Euler algorithm and the piecewise parabolic method (PPM) was selected in the calculation. This simulation investigated the explosion dynamics evolution in the lithotripsy area. The pressure and intensity of the calculus surface were calculated for different laser pulse energy and different distance between calculus and fiber tip. The calculation results indicate that the micro-explosion's properties are determined by the pulse energy, pulse duration and the water distance. Though Short pulse duration and large pulse energy cause high ablation efficiency, it mains more calculus retropulsion at the same time. The ideal surgery results need property laser parameters.

Er: YAG laser, the wavelength is 2940nm, can be absorbed strongly by water. The absorption coefficient is as high as 13000 cm−1. As the water strong absorption, Erbium laser can bring shallow penetration depth and smaller surrounding tissue injury in most soft tissue and hard tissue. At the same time, the interaction between 2940nm radiation and biological tissue saturated with water is equivalent to instantaneous heating within limited volume, thus resulting in the phenomenon of micro-explosion to removal organization. Different parameters can be set up to cut enamel, dentin, caries and soft tissue. For the development and optimization of laser system, it is a practical choice to use laser modeling to predict the influence of various parameters for laser performance. Aim at the status of low Erbium laser output power, flash-pumped Er: YAG laser performance was simulated to obtain optical output in theory. the rate equation model was obtained and used to predict the change of population densities in various manifolds and use the technology of Q-switch the simulate laser output for different design parameters and results showed that Er: YAG laser output energy can achieve the maximum average output power of 9.8W under the given parameters. The model can be used to find the potential laser systems that meet application requirements.