Topotactic Transformation Research Articles

Integrated 3D Open Network of Interconnected Bismuthene Arrays for Energy-Efficient and Electrosynthesis-Assisted Electrocatalytic CO2 Reduction.

Electrocatalytic CO2 reduction reaction (CO2 RR) toward formate production can be operated under mild conditions with high energy conversion efficiency while migrating the greenhouse effect. Herein, an integrated 3D open network of interconnected bismuthene arrays (3D Bi-ene-A/CM) is fabricated via in situ electrochemically topotactic transformation from BiOCOOH nanosheet arrays supported on the copper mesh. The resulted 3D Bi-ene-A/CM consists of 2D atomically thin metallic bismuthene (Bi-ene) in the form of an integrated array superstructure with a 3D interconnected and open network, which harvests the multiple structural advantages of both metallenes and self-supported electrodes for electrocatalysis. Such distinctive superstructure affords the maximized quantity and availability of the active sites with high intrinsic activity and superior charge and mass transfer capability, endowing the catalyst with good CO2 RR performance for stable formate production with high Faradaic efficiency (≈90%) and current density (>300mA cm-2 ). Theoretical calculation verifies the superior intermediate stabilization of the dominant Bi plane during CO2 RR. Moreover, by further coupling anodic methanol oxidation reaction, an exotic electrolytic system enables highly energy-efficient and value-added pair-electrosynthesis for concurrent formate production at both electrodes, achieving substantially improved electrochemical and economic efficiency and revealing the feasibility for practical implementation.

Doping- and Strain-Dependent Electrolyte-Gate-Induced Perovskite to Brownmillerite Transformation in Epitaxial La1-xSrxCoO3-δ Films.

Much recent attention has focused on the voltage-driven reversible topotactic transformation between the ferromagnetic metallic perovskite (P) SrCoO3-δ and oxygen-vacancy-ordered antiferromagnetic insulating brownmillerite (BM) SrCoO2.5. This is emerging as a paradigmatic example of the power of electrochemical gating (using, e.g., ionic liquids/gels), the wide modulation of electronic, magnetic, and optical properties generating clear application potential. SrCoO3 films are challenging with respect to stability, however, and there has been little exploration of alternate compositions. Here, we present the first study of ion-gel-gating-induced P → BM transformations across almost the entire La1-xSrxCoO3 phase diagram (0 ≤ x ≤ 0.70), under both tensile and compressive epitaxial strain. Electronic transport, magnetometry, and operando synchrotron X-ray diffraction establish that voltage-induced P → BM transformations are possible at essentially all x, including x ≤ 0.50, where both P and BM phases are highly stable. Under small compressive strain, the transformation threshold voltage decreases from approximately +2.7 V at x = 0 to negligible at x = 0.70. Both larger compressive strain and tensile strain induce further threshold voltage lowering, particularly at low x. The P → BM threshold voltage is thus tunable, via both composition and strain. At x = 0.50, voltage-controlled ferromagnetism, transport, and optical transmittance are then demonstrated, achieving Curie temperature and resistivity modulations of ∼220 K and at least 5 orders of magnitude, respectively, and enabling estimation of the voltage-dependent Co valence. The results are analyzed in the context of doping- and strain-dependent oxygen vacancy formation energies and diffusion coefficients, establishing that it is thermodynamic factors, not kinetics, that underpin the decrease in the threshold voltage with x, that is, with increasing formal Co valence. These findings substantially advance the practical and mechanistic understanding of this voltage-driven transformation, with fundamental and technological implications.

The effect of SrFeO2.5 native point defects on its electrical properties: First principles investigations

Determining microscopic origin of electronic conductivity in strontium ferrites is a pivotal step toward accomplishing control of a reversible topotactic phase transformation. This functionality is essential for use of these oxides in resistive switching non-volatile memory devices and future neuromorphic computing. Here, we use first principles computations for in-depth study of native defects and their effect on electronic structure in SrFeO2.5. We elucidate the role native defects play and show that an uptake of oxygen in diluted concentrations leads to a p-type conductivity in the SrFeO2.5. We identify two acceptor defect transition states at 0.25 eV for atomic and 0.1 eV for molecular oxygen interstitials.

Single-Step Topochemical Synthesis of NiFe Layered Double Hydroxides for Superior Anion Removal from Aquatic Systems.

Layered double hydroxides (LDHs) have attracted significant attention as adsorbents for the removal of anions from wastewater. However, it is challenging to develop a simple, economical, and environmentally friendly method for fabricating efficient LDH adsorbents. In this paper, we present an alternative approach for preparing a superb NiFe LDH adsorbent via a single-step topochemical synthesis method based on density functional theory (DFT) calculation. The NiFe LDH adsorbent [Ni0.75Fe0.25(OH)2]·(CO3)0.125·0.25H2O was obtained via the topotactic transformation of an oxide precursor (NaNi0.75Fe0.25O2), which was prepared by utilizing the high-temperature flux method, in ultrapure water. When the oxide precursor was soaked in ultrapure water, the host layer valence state changed from Ni3+ and Fe3+ to Ni2+ and Fe3+, and carbonate (CO32-) ions were simultaneously intercalated in the interlayer. Thereafter, the CO32- ions were deintercalated by Cl- ions to increase the adsorption capacity. The adsorbent exhibited high crystallinity, cation state, and porosity, and unique particle shape. In addition, it showed superior adsorption capacities of approximately 194.92, 176.15, and 146.28 mg g-1 toward phosphate, fluoride, and nitrate ions, respectively. The adsorption capacity toward all the anions reached over 70% within 10 min. The adsorption behavior was investigated by performing from adsorption kinetics, isotherm, and thermodynamics studies. The results showed that the anions were endothermically and spontaneously chemisorbed through an ion exchange process onto the adsorbent in a monolayer. In addition, the as-prepared NiFe LDH adsorbent showed high stability after multicycle testing.

Epitaxial Electrodeposition of 2D-Layered BiI3 and Conversion to Highly Ordered Bi-Based Organic−Inorganic Halide-Based Perovskites

Highly-ordered, epitaxial semiconductor thin films have low defect densities and excellent photo-physical properties that are desired for optoelectronic devices. Single crystalline perovskite materials are known to provide lower trap densities, a larger diffusion length, and higher photo-conversion efficiencies in perovskite solar cells.However, the preparation of cost-effective, highly ordered semiconductor films with a uniform surface morphology, low electron−hole recombination, and low trap densities remains a bottleneck to achieve higher device efficiencies in large-area electronics. Electrodeposition is a deposition route that is highly scalable and provides a variety of deposition parameters such as potential, pH, temperature, and additives that can be tuned to produce highly ordered epitaxial films with controlled morphologies.Bismuth triiodide, BiI3, is a 2D-metal halide semiconductor that crystallizes in a R3̅ (H) space group symmetry with lattice parameters of a = b = 0.7516 nm, c = 2.0718 nm. BiI3 possesses a structure with repeating units of the I−Bi−I plane, in which a monolayer of Bi atoms is sandwiched between two layers of iodide with strong Bi−I ionic bonds. We deposited epitaxial BiI3 films on Au(111) substrate electrochemically by reducing I2 in the presence of Bi3+. The epitaxial films of the solar light-absorbing perovskite (CH3NH3)3Bi2I9 are produced in a solution from BiI3 by topotactic transformation. Our deposition methods are outlined in figure 1. Epitaxially grown BiI3 on Au(111) shows highly ordered [001] out-of-plane orientation having the epitaxial relationship with the substrate as BiI3(0001)[1̅1̅20 ± 3°]//Au(111)[1̅1̅2], determined by X-ray pole figures. The lattice mismatch is minimized by the (±)3° rotation of the film relative to the substrate. The X-ray rocking curve shows that single-crystal-like BiI3 has a mosaic spread with full width at half-maximum (FWHM) of about ∼ 0.69°. The topotactic transformation of BiI3 produces a highly ordered [001]-oriented epitaxial perovskite (CH3NH3)3Bi2I9. The band gaps of BiI3 and converted (CH3NH3)3Bi2I9 film are measured using Tauc plot and found to be Eg ~ 1.76 eV and Eg ~ 2.15 eV.

Insights on Luminescent Micro- and Nanospheres of Infinite Coordination Polymers.

Coordination polymers have been extensively studied in recent years. Some of these materials can exhibit several properties such as permanent porosity, high surface area, thermostability and light emission, as well as open sites for chemical functionalization. Concerning the fact that this kind of compounds are usually solids, the size and morphology of the particles are important parameters when an application is desired. Inside this context, there is a subclass of coordination polymers, named infinite coordination polymers (ICPs), which auto-organize as micro- or nanoparticles with low crystallinity. Specifically, the particles exhibiting spherical shapes and reduced sizes can be better dispersed, enter cells much easier than bulk crystals and be converted to inorganic materials by topotactic transformation. Luminescent ICPs, in particular, can find applications in several areas, such as sensing probes, light-emitting devices and bioimaging. In this review, we present the state-of-the-art of ICP-based spherical particles, including the growth mechanisms, some applications for luminescent ICPs and the challenges to overcome in future commercial usage of these materials.

Recent Advances in Layered-Double-Hydroxides Based Noble Metal Nanoparticles Efficient Electrocatalysts.

With the energy crisis and environmental pollution becoming more and more serious, it is urgent to develop renewable and clean energy. Hydrogen production from electrolyzed water is of great significance to solve the energy crisis and environmental problems in the future. Recently, layered double hydroxides (LDHs) materials have been widely studied in the electrocatalysis field, due to their unique layered structure, tunable metal species and highly dispersed active sites. Moreover, the LDHs supporting noble metal catalysts obtained through the topotactic transformation of LDHs precursors significantly reduce the energy barrier of electrolyzing water, showing remarkable catalytic activity, good conductivity and excellent durability. In this review, we give an overview of recent advances on LDHs supporting noble metal catalysts, from a brief introduction, to their preparation and modification methods, to an overview of their application in the electrocatalysis field, as well as the challenges and outlooks in this promising field on the basis of current development.

The rhizosphere of tropical grasses as driver of soil weathering in embryonic Technosols (SE-Brazil)

The rhizosphere is a highly biogeochemically active site influencing several soil processes that are crucial for soil formation (e.g., mineral weathering). We studied weathering processes in embryonic Technosols constructed with limestone mine spoils, cultivated with sugarcane for two and six years (illitic siltstone areas: SC2 and SC6) and forage grasses (mainly Urochloa spp.) for 20 years (smectitic black shale area: P20). Rhizosphere and bulk soils were characterized through biological, chemical, and mineralogical analyses. We found contrasting biogeochemical environments when comparing rhizosphere and bulk soils. The pH values were about 1 unit lower, dissolved organic carbon concentrations were up to 3 times higher, and the average enzymatic activity was about 3 times higher in the rhizosphere soils compared to the bulk soils of the studied Technosols. A higher biological activity in the rhizosphere triggered the weathering of primary minerals (dolomite, feldspar, muscovite, quartz), causing the release of K, Ca, Mg, and Si from the mineral structure into the soil solution. The enrichment of the rhizospheric soil solution with Si and bases (mainly Ca and Mg) triggered the transformation of clay minerals and led to the formation of amorphous Si phases. Under sugarcane, smectite content increased from 18% in the siltstone to 44% in the SC6 rhizosphere. Under forage grasses, there was an increase in smectite contents from 58% in the black shale to 75% in both the rhizosphere and bulk soils. The main clay transformation process was a topotactic transformation from illite to smectite through progressive interstratification, supplied by the high availability of Si, Ca, and Mg in the rhizosphere. Our results highlight the pivotal role of rhizospheric processes in mineral weathering of Technosols developed from limestone mine waste. These processes may accelerate pedogenesis, and, consequently, the recovering of the soil functions essential for mine reclamation processes.

Interfacial Bifunctional Effect Promoted Non-Noble Cu/FeyMgOx Catalysts for Selective Hydrogenation of Acetylene

Non-noble metal-based catalysts are gradually employed for the conversion of the unsaturated carbon–carbon bond, which exhibits improved selectivity but at the expense of catalytic activity. Herein, in this work, an FeyMgOx-modified Cu interfacial structure with different Cu/Fe ratios was constructed by a structural topotactic transformation of layered double hydroxides, in which Cu-Fe0.16MgOx displayed an enhanced catalytic behavior (95% of selectivity at 100% of conversion and turnover frequency (TOF) of 0.048 s–1) in selective hydrogenation of acetylene. By virtue of X-ray absorption spectroscopy, reaction kinetic models, and the calculation based on density functional theory on analyzing the Cu-FeyMgOx interfacial structure, we demonstrated the formation of the low coordinated Cuδ−-Fe0.16δ+MgOx interfacial sites and further unraveled their dual functions. Specifically, the interfacial Cuδ− sites played a role in the activation of acetylene and hydrogen, while the formed intermediate bounded with the interfacial Cu atom and the interfacial Fe atom, respectively, which was favorable for the desorption to produce ethylene instead of over hydrogenation. This study offers a basic understanding on bifunctional interfacial catalysis for the conversion of the unsaturated carbon–carbon bond, which is of constructive significance for the rational design and preparation of supported non-noble metal materials with high efficiency.

The formation of impact coesite

Coesite in impact rocks is traditionally considered a retrograde product formed during pressure release by the crystallisation of an amorphous phase (either silica melt or diaplectic glass). Recently, the detailed microscopic and crystallographic study of impact ejecta from Kamil crater and the Australasian tektite strewn field pointed in turn to a different coesite formation pathway, through subsolidus quartz-to-coesite transformation. We report here further evidence documenting the formation of coesite directly from quartz. In Kamil ejecta we found sub-micrometric single-coesite-crystals that represent the first crystallization seeds of coesite. Coesite in Australasian samples show instead well-developed subeuhedral crystals, growing at the expenses of hosting quartz and postdating PDF deformation. Coesite (010) plane is most often parallel to quartz {10–11} plane family, supporting the formation of coesite through a topotactic transformation. Such reaction is facilitated by the presence of pre-existing and shock-induced discontinuities in the target. Shock wave reverberations can provide pressure and time conditions for coesite nucleation and growth. Because discontinuities occur in both porous and non-porous rocks and the coesite formation mechanism appears similar for small and large impacts, we infer that the proposed subsolidus transformation model is valid for all types of quartz-bearing target rocks.

Solid-state electrolyte gated synaptic transistor based on SrFeO2.5 film channel

In the past few years, synaptic device has become a hot topic in material science because of the urgent demand of neuromorphic computing. Ionic liquids gated three-terminal synaptic transistors have drawn extensive attention due to their outstanding energy efficiency, linearity, and symmetry. However, utilization of liquid electrolyte is not appropriate for the requirement of the practical application. Herein, a novel three-terminal synaptic transistor is designed and constructed using a solid-state electrolyte gate and a brownmillerite SrFeO2.5 thin film channel. Topotactic phase transformation can be induced between insulative brownmillerite SrFeO2.5 and conductive perovskite SrFeO3−δ. Nonvolatile conductance switching of the SrFeOx film can be realized by inserting and extracting of oxygen ions with electrolyte gating. The essential synaptic learning functions including excitatory postsynaptic current, and short-term/long-term plasticity, are successfully mimicked in the three-terminal synaptic transistor. This synapse device achieves a large scale adjusted range and multistable plasticity, demonstrating a new way to achieve key component of upcoming neuromorphic circuitry.

FeNi3/NiFe-Mixed Metal Oxide Heterostructured Nanosheets for Catalytic Nitro-Amination

The two-dimensional heterostructured FeNi3/NiFe-mixed metal oxide porous nanocatalyst has been constructed through the coprecipitation-phase-transformation process, in which a large amount of interfaces and micropores caused by the topotactic transformation can expose abundant active sites, thus promoting catalytic activity. Simultaneously, by virtue of the strong interaction between metals and metal oxides derived from the in situ partial reduction, the uniform FeNi3 phases can be stably fixed on NiFe-MMO nanosheets. In such a designed FeNi3/NiFe-MMO nanocomposite, the synergistic effect between FeNi3 with excellent charge-transfer characteristics and the NiFe-MMO support with a selective adsorption of the −NO2 group in p-nitroaromatic compounds makes it have excellent catalytic performance of the nitro-amination reaction, especially for the amination of p-nitrophenol. The reaction rate constant k is as high as 0.08123 s–1, and there is no obvious performance degradation after 15 cycles of the reaction. This work provides a valid pathway for catalyzing the nitro-amination reaction.

Cation and anion topotactic transformations in cobaltite thin films leading to Ruddlesden-Popper phases

The ability to control a material's physical properties by ion migration is particularly important for the design of devices for emerging applications such as neuromorphic computing, magnetoionic switches, and next-generation memory and logic devices. The perovskite oxide LaSrCoO${}_{3}$ is an ideal system for investigating ion migration due to its high oxygen vacancy conductivity, relatively low oxygen vacancy formation energy, and strong coupling of the magnetic and electronic properties to its oxygen stoichiometry. This paper shows that it is possible to obtain a series of electronic and magnetic phases by systematically exposing the parent perovskite oxide to highly reducing annealing conditions. Under these conditions, the movement of both oxygen and cobalt ions in and out of the lattice represents a new direction for discovery of functional materials for brain-inspired computing.

Textured growth of Co-Fe-Ga alloy films via topotactic transformation from highly oriented precursor and spinel oxide

Textured growth of Co-Fe-Ga (CFG) alloy films by co-precipitation, low-temperature heat treatment (LTHT) at 333 K for 3 days, spin-coating, and post-annealing at 973 K for 30 min has been investigated. The X-ray diffraction measurements show that the CFG films made with LTHT are highly (110)-oriented bcc alloys, while those grown without LTHT are not oriented in a specific direction. The observed texture formation in the bcc alloy films results from topotactic transformation as indicated by the similarity of the ionic and atomic arrangements among the precursor, spinel oxide, and bcc alloy. The stabilization of the precursor by Ga3+ inclusion presumably plays an important role in the transformation process leading to the highly orientated spinel and CFG bcc alloy films.

Alkaline Water Splitting Enhancement by MOF-Derived Fe-Co-Oxide/Co@NC-mNS Heterostructure: Boosting OER and HER through Defect Engineering and In Situ Oxidation.

Introducing defects and in situ topotactic transformation of the electrocatalysts generating heterostructures of mixed-metal oxides(hydroxides) that are highly active for oxygen evolution reaction (OER) in tandem with metals of low hydrogen adsorption barrier for efficient hydrogen evolution reaction (HER) is urgently demanded for boosting the sluggish OER and HER kinetics in alkaline media. Ascertaining that, metal-organic-framework-derived freestanding, defect-rich, and in situ oxidized Fe-Co-O/Co metal@N-doped carbon (Co@NC) mesoporous nanosheet (mNS) heterostructure on Ni foam (Fe-Co-O/Co@NC-mNS/NF) is developed from the in situ oxidation of micropillar-like heterostructured Fe-Co-O/Co@NC/NF precatalyst. The in situ oxidized Fe-Co-O/Co@NC-mNS/NF exhibits excellent bifunctional properties by demanding only low overpotentials of 257 and 112mV, respectively, for OER and HER at the current density of 10mAcm-2 , with long-term durability, attributed to the existence of oxygen vacancies, higher specific surface area, increased electrochemical active surface area, and in situ generated new metal (oxyhydr)oxide phases. Further, Fe-Co-O/Co@NC-mNS/NF (+/-) electrolyzer requires only a low cell potential of 1.58V to derive a current density of 10mAcm-2 . Thus, the present work opens a new window for boosting the overall alkaline water splitting.

Topotactic transformation of (T-T’) La1.8Nd0.2CuO4: Synthesis, structure, electrical properties and oxygen diffusion pathways simulation

The starting sample T-La1.8Nd0.2CuO4 (SG: Bmab) has been synthesized by the conventional solid-state reaction at 900 °C. The T′-La1.8Nd0.2CuO4 (SG: I4/mmm) sample has been obtained via a topotactic reduction reaction of T-La1.8Nd0.2CuO4 (SG: Bmab) using CaH2 (as reductor) followed by an oxidation at 400 °C in air. The temperature of the phase transition (T-T′) has been determined using the differential thermal analysis (DTA) and the temperature-dependent powder X-ray diffraction (TDXD). The crystal structures of the title compounds have been refined by using the Rietveld method and confirmed by the means of the charge distribution model (CHARDI). The electrical properties of the title compounds have been studied by impedance complex spectroscopy between 200 °C and 650 °C. This study shows two slopes in the Arrhenius plot with experimental activation energies 1.033 eV and 1.657 eV which correspond to the reduced phase and the T′ phase respectively. The simulation of oxygen diffusion in structures by using the Bond Valence Site Energy (BVSE) method shows three-dimensional pathways of oxygen diffusion. The calculated activation energies of the T′ and T structure are 1.619 and 2.369 eV, respectively.

1D/2D constructed Bi2S3/Bi2O2CO3 direct Z-Scheme heterojunction: A versatile photocatalytic material for boosted photodegradation, photoreduction and photoelectrochemical detection of water-based contaminants

In this work, two-dimensional Bi2O2CO3 disk is synthesized, followed by the growth of Bi2S3 over Bi2O2CO3 via topotactic transformation by controlling the amount of thiourea under hydrothermal conditions. The synthesized composite catalyst is investigated for photocatalytic oxidation and reduction of tetracycline hydrochloride and hexavalent chromium under visible light irradiation. High interfacial contact between the Bi2O2CO3 disk0 and Bi2S3 fiber is confirmed via high-resolution microscopic imaging. Enhanced light absorption and increased charge carrier separation is observed after the formation of the Bi2S3/Bi2O2CO3 composite. The Bi2S3/Bi2O2CO3 composite grown using 1 mmol of thiourea shows approximately 98% degradation of tetracycline hydrochloride after 120 min and 99% Cr(VI) reduction after 90 min of photochemical reaction under visible light irradiation. The charge separation is due to the formed internal electric field at the interface, which upon light irradiation follows a z-scheme charge transfer hindering the recombination at the Bi2S3 and Bi2O2CO3 interface, thereby contributing efficiently to the photochemical process. In addition, the mechanism of the photochemical reaction for the degradation of pollutants is supported using quencher and probe experiments. Furthermore, photoelectrochemical detection of antibiotic in aqueous solution is conducted to understand the sensing feasibility of the synthesized system.

Hydrangea-like Superstructured Micro/Nanoreactor of Topotactically Converted Ultrathin Bismuth Nanosheets for Highly Active CO2 Electroreduction to Formate.

An electrocatalytic carbon dioxide reduction reaction (CO2RR) is an appealing route to obtain the value-added feedstocks and alleviate the energy crisis. However, how to achieve high-performance electrocatalysts for CO2 reduction to formate is challenging owing to the poor intrinsic activity, insufficient conductivity, and low surface density of active sites. Herein, we fabricated an extremely active and selective hydrangea-like superstructured micro/nanoreactor of ultrathin bismuth nanosheets through an in situ electrochemical topotactic transformation of hierarchical bismuth oxide formate (BiOCOOH). The resulted bismuth nanosheet superstructure is in the form of three-dimensional intercrossed networks of ultrathin nanosheets, forming an ordered open porous structure through self-assembly, which can be used as a micro/nanoreactor to enable a large electrochemically active surface area as well as high atomic utilization. Such a distinctive nanostructure endows the material with high electrocatalytic performances for CO2 reduction to formate with near-unity Faradaic selectivity (>95%) in a wide potential window from -0.78 to -1.18 V. Furthermore, this micro/nanoreactor can give the high current densities over 300 mA cm-2 at low applied potentials without compromising selectivity in a flow cell reactor. Density functional theory (DFT) and in situ attenuated total reflection-infrared spectroscopy (in situ ATR-IR) were further conducted to interpret the CO2RR mechanisms.

Ultrathin chalcogenide nanosheets for photoacoustic imaging-guided synergistic photothermal/gas therapy

Previous preclinical and clinical studies have shown that using only a single therapy makes it difficult to completely eradicate tumors and restrain cancer metastasis. To overcome this challenge, multi-modal synergistic treatments have attracted considerable attention. Herein, an ultrathin Cu-loaded CoCuFe-selenide (CCFS) was prepared by a facile topotactic transformation from CoCuFe layered double hydroxide (LDH) nanosheets (NSs), followed by surface modification with polyvinyl pyrrolidone (PVP) and l-arginine (L-Arg). The resultant CCFS-PVP-L-Arg (CPA) system shows excellent synergetic photothermal and gas therapy (PTT/GT). The CCFS NSs have strong LSPR absorbance characteristic, with enhanced light absorption in the near-infrared (NIR) region. This endows the CPA nanocomposite with an outstanding photothermal conversion efficiency of 72.0% (pH 7.4) and 81.0% (pH 5.4), among the highest reported for 2D chalcogenide nanomaterials. In addition, NO release from CPA is triggered by decomposition of L-Arg in the H2O2-rich and acidic tumor microenvironment, permitting localized NO gas therapy in the tumor site. In vitro experiments revealed 91.8% apoptosis of HepG2 cells, and in vivo studies showed complete tumor elimination upon treatment with the CPA nanocomposite under NIR irradiation. To the best of our knowledge, this is the first report of combined defect-induced high-efficiency PTT with H2O2 and pH targeted GT.

New Composite Nanostructure ZnO Derived from ZnS(en)0.5

The morphology of ZnS(en)0.5 (en is ethylenediamine) has a significant influence on its derived ZnS and ZnO. Herein, we study the impact of the amount of ethylenediamine (EDA) and ultrasonic device with different power on the preparation of ZnS(en)0.5 nanosheets. The more EDA and the lower power ultrasonic device make the thinner nanosheets. After annealing the ZnS(en)0.5 at a different temperature, the porous ZnS and composite nanostructure ZnO are obtained. The ZnS annealed at 450°C with sheet structure has many holes. For the ZnO annealed at 550°C, the unique edge belt-like structure is firstly discovered and the interior is still porous sheet. The belt-like structure is speculated to the topotactic transformation of the ZnS to ZnO.