Preparation of cauliflower-like bismuth sulfide and its application in electrochemical sensor

A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide （DMF） solution of bismuth nitrate [Bi（NO3）3.5H2O] and thioacetamide （TAA） with 2-undecyl-1-dithioureido-ethyl-imidazoline （SUDEI） as the morphology-controlling agent. The obtained Bi2S3 products were characterized by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and X-ray diffraction （XRD）, etc. The sensing properties of Bi2S3 with different morphologies were evaluated by the electrochemical analysis of dopamine （DA） and ascorbic acid （AA） coexisting solution. The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneous determination of DA and AA,

Spectral computed tomography-guided photothermal therapy of osteosarcoma by bismuth sulfide nanorods

Osteosarcoma(OS)is the most normally primary malignant bone cancer in adolescents.Due to their analogous X-ray attenuation properties,healthy bones and malignancies with iodine enhancement cannot be distinguished by conventional computed tomography(CT).As one kind of spectral CT,dual-energy CT(DECT)offers multiple functions for material separation and cancer treatments.Herein,bismuth sulfide(Bi_(2)S_(3))nanorods(NRs)were synthesized as special contrast agents(CAs)for DECT,which have superior imaging properties than clinical iodine CAs.At the same time,the high photothermal conversion rates of Bi_(2)S_(3)NRs can be used for DECT-guided photothermal therapy(PTT)to destroy OS and inhibit tumor growth under the guidance of DECT imaging.Importantly,DECT imaging real-timely monitored that PTT could accelerate the diffusion of Bi2S3 NRs in the tumor,obtaining detailed information on the internal distribution of nanomaterials in tumors around the bone to avoid injury to normal tissues by PTT.Overall,the proposed strategy of DECT imaging-guided PTT appears enormous promise for bone disease treatment.

Biomolecule-assisted Solvothermal Synthesis of Bismuth Sulfide Nanorods

A simple biomolecule-assisted synthetic route has been successfully developed to prepare bismuth sulfide（Bi 2 S 3 ） nanorods under solvothermal conditions.In the synthetic system,pentahydrate bismuth nitrate was employed to supply Bi source and L-cystine was used as sulfide source and complexing agent.The morphology,structure,and phase composition of the as-prepared Bi 2 S 3 products were characterized by X-ray diffraction（XRD）,energy dispersion spectroscopy（EDS）,X-ray photoelectron spectroscopy（XPS）,field-emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM）,selected area electron diffraction（SAED）,and high-resolution transmission electron microscopy（HRTEM）.The experimental results show that the nanorods have uniform diameter of 100-200 nm and length of 2-4 μm.The possible formation mechanism for the bismuth sulfide nanorods was discussed.

Multilayer Strategy for Photoelectrochemical Hydrogen Generation:New Electrode Architecture that Alleviates Multiple Bottlenecks

Years of research have demonstrated that the use of multiple components is essential to the development of a commercial photoelectrode to address specific bottlenecks,such as low charge separation and injection efficiency,low carrier diffusion length and lifetime,and poor durability.A facile strategy for the synthesis of multilayered photoanodes from atomic-layer-deposited ultrathin films has enabled a new type of electrode architecture with a total multilayer thickness of 15–17 nm.We illustrate the advantages of this electrode architecture by using nanolayers to address different bottlenecks,thus producing a multilayer photoelectrode with improved interface kinetics and shorter electron transport path,as determined by interface analyses.The photocurrent density was twice that of the bare structure and reached a maximum of 33.3±2.1 mA cm^(−2) at 1.23 VRHE.An integrated overall water-splitting cell consisting of an electrocatalytic NiS cathode and Bi_(2)S_(3)/NiS/NiFeO/TiO_(2) photoanode was used for precious-metal-free seawater splitting at a cell voltage of 1.23 V without degradation.The results and root analyses suggest that the distinctive advantages of the electrode architecture,which are superior to those of bulk bottom-up core–shell and hierarchical architectures,originate from the high density of active sites and nanometer-scale layer thickness,which enhance the suitability for interface-oriented energy conversion processes.

Integrated sensor based on acoustics-electricity-mechanics coupling effect for wireless passive gas detection

Integrated sensor combines multiple sensor functions into a single unit,which has the advantages of miniaturization and better application potential.However,limited by the sensing platforms of the sensor and the selectivity of the sensitive film,there are still challenges to realize multi-component gas detection in one unit.Herein,a principle integration method is proposed to achieve the multi-component gas detection based on the acoustics-electricity-mechanics coupling effect.The electrical and mechanical properties of the Bi_(2)S_(3)nanobelts materials in different atmospheres indicate the possibility of realizing the principle integration.At the same time,the surface acoustic wave(SAW)sensor as a multivariable physical transducer can sense both electrical and mechanical properties.Upon exposure to 10 ppm NO_(2),NH_(3),and their mixtures,the integrated SAW gas sensor shows a 4.5 kHz positive frequency shift(acoustoelectric effect),an 11 kHz negative frequency shift(mechanics effects),and a reduced 4 kHz negative frequency shift(acoustics-electricity-mechanics coupling effect),respectively.Moreover,we realize wireless passive detection of NO_(2)and NH_(3)based on the SAW sensor.Our work provides valuable insights that can serve as a guide to the design and fabrication of single sensors offering multi-component gas detection via different gas sensing mechanisms.

Nanostructured Bi2S3 encapsulated within three- dimensional N-doped graphene as active and flexible anodes for sodium-ion batteries

Sodium-ion batteries （SIBs） have been increasingly attracting attention as a sustainable alternative to lithium-ion batteries for scalable energy storage. The key to advanced SIBs relies heavily upon the development of reliable anodes. In this respect, Bi2S3 has been extensively investigated because of its high capacity, tailorable morpholog, and low cost However, the common practices of incorporating carbon species to enhance the electrical conductivity and accommodate the volume change of Bi2S3 anodes so as to boost their durability for Na storage have met with limited success. Herein, we report a simple method to realize the encapsulation of Bi2S3 nanorods within three-dimensional, nitrogen-doped graphene （3DNG） frameworks, targeting flexible and active composite anodes for SIBs. The Bi2S3/ 3DNG composites displayed outstanding Na storage behavior with a high reversible capacity （649 mAh·g^-1 at 62.5 mA·g^-1） and favorable durability （307 and 200 mAh·g^-1 after 100 cycles at 125 and 312.5 mA·g^-1, respectively）. In-depth characterization by in situ X-ray diffraction revealed that the intriguing Na storage process of Bi2Sa was based upon a reversible reaction. Furthermore, a full, flexible SIB cell with Na0.4MnO2 cathode and as-prepared composite anode was successfully assembled, and holds a great promise for next-generation, wearable energy storage applications.

High thermoelectric properties realized in earth abundant Bi_(2)S_(3) bulk materials via Se and Cl co-doping in solution synthesis process

Bi_(2)S_(3)-based alloys are considered promising thermoelectric materials due to their large Seebeck coefficient and low lattice thermal conductivity.However,low electrical conductivity usually leads to poor electrical transport properties,which seriously restricts their further application in thermoelectric refrigeration and/or power generation.In this work,Bi_(2)S_(3) with high electrical transport properties is synthesized hydrothermally via Se and Cl co-doping.The maximum electrical conductivity value of 483 S cm^(-1) was obtained for the Bi_(2)S_(2.4)Se_(0.4)Cl_(0.20) sample at room temperature.The significant improvement of electrical conductivity gives rise to a high average power factor of 411μW m^(-1) K^(-2) during the measuring temperature range and a peak value of 456μW m^(-1) K^(-2) at 673 K.Benefiting from the largely improved electrical transport properties,a superior ZT value of approximately 0.66 and ZTave.of 0.36 were obtained for Bi_(2)S_(2.4)Se_(0.4)Cl_(0.20),and the theoretically calculated conversion efficiency reached 5.7%.The results indicate that Bi_(2)S_(3) is a promising candidate for thermoelectric applications at medium temperatures.

Synergistically enhanced thermoelectric properties of Bi_(2)S_(3) bulk materials via Cu interstitial doping and BiCl_(3) alloying

Bi_(2)S_(3)is composed of inexpensive and environ-mental friendliness elements,which has received extensive interests and been investigated as a promising mid-tempera-ture thermoelectric material for years.Even pure Bi_(2)S_(3)pos-sesses a high Seebeck coefficient and low thermal conductivity,its low electrical conductivity leads to a lowfigure of merit(ZT)value.In this work,Bi_(2)S_(3)fabricated by solid-state melting combined with spark plasma sintering can significantly enhance the thermoelectric performance via introducing small amounts of Cu and BiCl_(3).Cu interstitial doping and Cl substitution on S site result in a large increase in electrical conductivity.Additionally,the enhanced phonon scattering is derived from the point defects caused by element doping,the grain boundaries,and the small amount of sec-ondary phase,which leads to the low thermal conductivity.Finally,a high ZT value of 0.7 is obtained at 773 K and reaches a large average ZT of 0.36 in the temperature range from room temperature(RT)to 773 K for the Cu-interstitial-doped and BiCl_(3)-alloyed(Cu_(0.01)Bi_(2)S_(3)+0.175 mol%BiCl_(3))sample.Furthermore,the mechanical properties of the Cu_(0.01)Bi_(2)S_(3)+0.175 mol%BiCl_(3)sample are lower than those of other Bi_(2)S_(3)samples,which stem from the weak chemical bonding strength.

Poly(arylene ether nitrile)Dielectric Film Modified by Bi_(2)S_(3)/rGO-CN Fillers for High Temperature Resistant Electronics Fields

High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film capacitor.In this work,a novel high-temperature-resistant dielectric film was prepared.Firstly,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the materials.Compared with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at break.The dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 kHz.Moreover,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.

Morphology Control of Bi2S3 Nanostructures and the Formation Mechanism

Bismuthinite （Bi2S3）nanostructures were prepared by a hydrothermal method with sodium ethylenediamine- tetraacetate （EDTA-Na2）. The morphology of Bi2S3 nanostructures was changed from a nanorod to a nanoplate by presence of the EDTA-Na2. The altered morphology was caused by the capping effect of EDTA-Na2 with Bi3＋ ions, which induces the suboptimal growth direction due to partially blocking the preferential orientation direction. When the EDTA-Na2/Bi3＋ molar ratio= 1, the growth of Bi2S3 nanostructures was not allowed due to the chelating effect of EDTA-Na2. The obtained Bi2S3 nanorods, stacked nanorods, nanoplates and nanoparticles were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron mi- croscopy （HRTEM） and selected area electron diffraction （SAED） pattern. A possible formation mechanism of these morphologies was proposed. The successful synthesis of various morphologies of nanostructured Bi2S3 may open up new possibilities for thermoelectric, electronic and optoelectronic uses of nanodevices based on Bi2S3 nanostructure.