Deformable Catalytic Material Derived from Mechanical Flexibility for Hydrogen Evolution Reaction

Deformable catalytic material with excellent flexible structure is a new type of catalyst that has been applied in various chemical reactions,especially electrocatalytic hydrogen evolution reaction(HER).In recent years,deformable catalysts for HER have made great progress and would become a research hotspot.The catalytic activities of deformable catalysts could be adjustable by the strain engineering and surface reconfiguration.The surface curvature of flexible catalytic materials is closely related to the electrocatalytic HER properties.Here,firstly,we systematically summarized self-adaptive catalytic performance of deformable catalysts and various micro–nanostructures evolution in catalytic HER process.Secondly,a series of strategies to design highly active catalysts based on the mechanical flexibility of lowdimensional nanomaterials were summarized.Last but not least,we presented the challenges and prospects of the study of flexible and deformable micro–nanostructures of electrocatalysts,which would further deepen the understanding of catalytic mechanisms of deformable HER catalyst.

Surface treatment of GaN nanowires for enhanced photoelectrochemical water-splitting

High-efficiency hydrogen production through photoelectrochemical(PEC)water splitting has emerged as a promising solution to address current global energy challenges.Ⅲ-nitride semiconductor photoelectrodes with nanostructures have demonstrated great potential in the near future due to their high light absorption,tunable direct band gap,and strong physicochemical stability.However,several issues,including surface trapping centers,surface Fermi level pinning,and surface band bending,need to be addressed.In this work,enhanced photovoltaic properties have been achieved using gallium nitride(GaN)nanowires(NWs)photoelectrodes by adopting an alkaline solution surface treatment method to reduce the surface states.It was found that surface oxides on NWs can be removed by an alkaline solution treatment without changing the surface morphology through X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and other characterization methods.These findings provide new insights to the development of high-efficiency photoelectrodes for new energy source applications.

The clinical effects of DC-CIK cells combined with chemotherapy in the treatment of advanced NSCLC

Objective: The aim of the study was to evaluate the safety and therapeutic effects of autologous dendritic cells co-cultured with cytokine-induced killer cells (DC-CIK) combined with chemotherapy in advanced non-small cell lung cancer (NSCLC) patients. Methods: Fifty patients with advanced NSCLC (stages III to IV), who had received therapies in our Center (Department of Biotherapy, Affiliated to Cancer Hospital of Shanxi Medical University, Taiyuan, China) from August 2008 to January 2010, were treated by DC-CIK + chemotherapy as the combined treatment group; fifty advanced NSCLC patients treated with chemotherapy at the same time served as controls. The immunologic function, short-term therapeutic effects, the 1-year survival rate, the life quality, the chemotherapy side effects were compared between the two groups, the safety and therapeutic effects of DC-CIK cells therapy were observed too. Results: There was no obvious change of subsets of T cells in peripheral blood before and after therapy in DC-CIK + chemotherapy group, and IFN-γ was improved after therapy in this group (P < 0.05); in chemotherapy alone group, the ratios of CD3+CD4+, CD3+CD8+, CD3-CD56+ cells and the secretion of IL-2, TNF-α decreased significantly after therapy (P < 0.05); the ratios of CD3+CD8+, CD3+CD56+ were improved after cell culture (P < 0.05). The disease control rate (DCR) of DC-CIK + chemotherapy group was higher than that in the chemotherapy alone group (78.0% vs 56.0%, P < 0.05); the 1-year survival rates of DC-CIK + chemotherapy group and chemotherapy alone group were 50% and 44% respectively, had no significant difference. Compared with chemotherapy alone group, the occurrence of chemotherapy side effects (including bone marrow suppression, nausea and vomiting, peripheral nerve toxicity) was less in the DC-CIK + chemotherapy group (P < 0.05). The physical and appetite were better in DC-CIK + chemotherapy group after therapy. Conclusion: To compare with simple chemotherapy, DC-CIK + chemotherapy for advanced NSCLC is safe and effective, and it can improve patients' life quality and remission rate, and prolong their survival time.

Fabrication and Characterization of GaN-Based Micro-LEDs on Silicon Substrate

GaN-based micro light emitting diodes(micro-LEDs) on silicon(Si)substrates with 40μm in diameter are developed utilizing standard photolithography and inductively coupled plasma etching techniques.From currentvoltage curves,the relatively low turn-on voltage of 2.8 V and low reverse leakage current in the order of 10-8 A/cm2 indicate good electrical characteristics.As the injection current increases,the electroluminescence emission wavelength hardly shifts at around 433 nm, and the relative external quantum efficiency slightly decays,because the impact of quantum-confined Stark effect is not serious in violet-blue micro-LEDs.Since GaN-LEDs are cost effective on large-area Si and suitable for substrate transfer or vertical device structures,the fabricated micro-LEDs on Si should have promising applications in the fields of high-resolution display and optical communication.

Low-threshold lasing in a plasmonic laser using nanoplate InGaN/GaN

Plasmonic nanolaser as a new type of ultra-small laser,has gain wide interests due to its breaking diffraction limit of light and fast carrier dynamics characters.Normally,the main problem that need to be solved for plasmonic nanolaser is high loss induced by optical and ohmic losses,which leads to the low quality factor.In this work,InGaN/GaN nanoplate plasmonic nanolaser with large interface area were designed and fabricated,where the overlap between SPs and excitons can be enhanced.The lasing threshold is calculated to be~6.36 kW/cm^(2),where the full width at half maximum(FWHM)drops from 27 to 4 nm.And the fast decay time at 502 nm(sharp peak of stimulated lasing)is estimated to be 0.42 ns.Enhanced lasing characters are mainly attributed to the strong confinement of electromagnetic wave in the low refractive index material,which improve the near field coupling between SPs and excitons.Such plasmonic laser should be useful in data storage applications,biological application,light communication,especially for optoelectronic devices integrated into a system on a chip.

High performance Ga N-based hybrid white micro-LEDs integrated with quantum-dots

Hybrid white micro-pillar structure light emitting diodes(LEDs)have been manufacture utilizing blue micro-LEDs arrays integrated with 580 nm CIS((CuInS2-ZnS)/ZnS)core/shell quantum dots.The fabricated hybrid white micro-LEDs have good electrical properties,which are manifested in relatively low turn-on voltage and reverse leakage current.High-quality hybrid white light emission has been demonstrated by the hybrid white micro-LEDs after a systemic optimization,in which the corresponding color coordinates are calculated to be(0.3303,0.3501)and the calculated color temperature is 5596 K.This result indicates an effective way to achieve high-performance white LEDs and shows great promise in a large range of applications in the future including micro-displays,bioinstrumentation and visible light communication.

Designing multi-heterogeneous interfaces of Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)hybrid for hydrogen evolution

The transition metal chalcogenides represented by MoS_(2)are the ideal choice for non-precious metal-based hydrogen evolution catalysts.However,whether in acidic or alkaline environments,the catalytic activity of pure MoS_(2)is still difficult to compete with Pt.Recent studies have shown that the electronic structure of materials can be adjusted by constructing lattice-matched heterojunctions,thus optimizing the adsorption free energy of intermediates in the catalytic hydrogen production process of materials,so as to effectively improve the electrocatalytic hydrogen production activity of catalysts.However,it is still a great challenge to prepare heterojunctions with lattice-matched structures as efficient electrocatalytic hydrogen production catalysts.Herein,we developed a one-step hydrothermal method to construct Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)(Ni-MoS_(2)on behalf of Ni doping MoS_(2))electrocatalyst with multiple heterogeneous interfaces which possesses rich catalytic reaction sites.The Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)electrocatalyst produced an extremely low overpotential of 69.4 mV with 10 mA·cm^(−2)current density for hydrogen evolution reaction(HER)in 1.0 M KOH.This work provides valuable enlightenment for exploring the mechanism of HER enhancement to optimize the surface electronic structure of MoS_(2),and provides an effective idea for constructing rare metal catalysts in HER and other fields.

Advanced development of grain boundaries in TMDs from fundamentals to hydrogen evolution application

Grain boundary(GB),as a kind of lattice defect,widely exists in two-dimensional transition metal dichalcogenides(2D TMDs),which has complex and diverse influences on the physical/chemical properties of 2D TMDs.GBs are universally considered to be a double-edged sword,although some electrical and mechanical properties of 2D TMDs would be adversely affected leading to the reduced overall quality,certain structure-oriented applications could be realized based on its unique properties.In this review,we first detailed the atomic structure characteristics of GBs and the corresponding techniques,then we systematically summarized the methods of introducing GBs into 2D TMDs.Next,we expounded unique electrical,mechanical,and chemical properties of the GBs in 2D TMDs and clarified its internal relationship with the atomic structure.Moreover,the application of GB structure in hydrogen evolution reaction(HER)is also discussed.In the end,we make a conclusion and put forward outlooks,hoping to further promote the basic research of GB and boost the wide application of 2D TMDs.

Versatile oxidized variants derived from TMDs by various oxidation strategies and their applications

The physicochemical properties of transition metal dichalcogenides(TMDs)are highly related to their structures and usually stable in air.However,under certain conditions they could be transformed into different structures due to oxidation.Considering this,various materials with fascinating structures have been explored by oxidation strategies,which possess novel properties and great potential in various applications such as solar batteries,hydrogen evolution reaction(HER)catalysts,and field effect transistors(FET).In this review,we systematically summarize the atomic structures of TMD oxidized variants and the corresponding fabrication approaches.Utilizing various characterization methods,the chemical components of TMD oxidized variants are illustrated.Furthermore,we expound the promising applications of the oxidized variants.This review is expected to provide a new insight for preparing precise materials at the atomic level through corresponding oxidation strategies.

Monolayer graphene/GaN heterostructure photodetector with UV‑IR dual‑wavelength photoresponses

An ultraviolet-infrared(UV-IR)dual-wavelength photodetector(PD)based on a monolayer(ML)graphene/GaN heterostructure has been successfully fabricated in this work.The ML graphene was synthesized by chemical vapor deposition(CVD)and subsequently transferred onto GaN substrate using polymethylmethacrylate(PMMA).The morphological and optical properties of the as-prepared graphene and GaN were presented.The fabricated PD based on the graphene/GaN heterostructure exhibited excellent rectify behavior by measuring the current–voltage(I–V)characteristics under dark conditions,and the spectral response demonstrated that the device revealed an UV-IR dual-wavelength photoresponse.In addition,the energy band structure and absorption properties of the ML graphene/GaN heterostructure were theoretically investigated based on density functional theory(DFT)to explore the underlying physical mechanism of the two-dimensional(2D)/three-dimensional(3D)hybrid heterostructure PD device.This work paves the way for the development of innovative GaNbased dual-wavelength optoelectronic devices,offering a potential strategy for future applications in the field of advanced photodetection technology.