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Purpose The purpose of this study is to test the concept of a relatively low cost but biocompatible customized surgical guide printing method using a new composite material for the FDM process to support accurate virtual model reconstruction in CT. Design/methodology/approach Current additive manufacturing printed surgical guides have problems of scanning artifacts or low computed tomography (CT) values for virtual model reconstruction in CT-assisted surgical operations. These tools always face difficulties in precise positioning due to the effect of human soft tissues and manually made unstable landmarks. To solve this problem, this paper proposes a modified material, polyetheretherketone powder mixed with barium sulfate powder, for printing customized surgical guides with relatively low cost to support a synchronized scanning strategy, for the accurate reconstruction of human tissues and in vitro models. Findings A set of benchmarking experiments and clinical simulation cases were conducted. The results showed that the proposed solution can be used to print surgical guides to form stable and clear CT graphs for three-dimensional digital model reconstruction. Human tissues and in vitro models can be accurately reconstructed using clear CT graphs without any scanning artifacts or difficulties in image segmentation for virtual model reconstruction, thus facilitating accurate operation guidance and positioning. Originality/value This method has wide application potential for printing modular or customized surgical guides with low cost and reusability, especially for surgical operations using CT-assisted navigation systems in underdeveloped regions where medical device costs are a critical issue.

Low photocurrent density of hematite (α-Fe2O3) originating from the inherent defects usually hinders its application in photoelectrochemical (PEC) water oxidation. In this paper, the synergetic effect of increase of oxygen vacancies and in-situ constructing heterojunction by coating MOFs on the α-Fe2O3 nanoarrays gives rise to the boosted photocurrent of α-Fe2O3 from 0.25 mA/cm2 to 2.1 mA/cm2 at 1.23 V (vs. RHE). The results showed that the appropriate energy band structure engineered by the presence of MOFs layer not only facilitated the PEC water oxidation, but also enhanced the light absorption performance. With inducing oxygen vacancies in further, the intrinsic conductivity of photoanode can be well ameliorated. The value of carrier density is improved one order higher to promote charge transfer between the interfaces and raise the carrier separation efficiency as a result.

Hexagonal boron nitride (h-BN) has been widely applied to different fields owing to its unique structural feature. Porous h-BN materials are promising CO2 adsorbents by virtue of the large specific surface area and intrinsic polarity. Here, porous few-layered h-BN nanosheets, which were synthesized using bulk graphitic carbon nitride (g-C3N4) as a template, presented high crystallinity with a thickness of ~5.5 nm. It exhibited unique high porosity with a specific surface area of 212.620 m2 g−1. Simultaneously, the material displayed excellent CO2 adsorption properties endowed to its porous nature and its optimal CO2 adsorption capacity could be 19.26 cm3 g−1 at 25 °C under atmospheric pressure. Based on thermodynamic calculations, the formation mechanism of porous few-layered 2D h-BN nanosheets with g-C3N4 as sacrificial templates was proposed.

Hybrid CdSe/CsPbI3 quantum dots (QDs) are selected for incorporation between the perovskite film and the hole transport layer (HTL). Owing to the high absorption coefficient and the suitable band gap of CsPbI3, an optimized energy level structure can be expected. Besides, energy transfer could be realized due to the overlap between the emission spectrum of CdSe QDs and the excitation spectrum of CsPbI3 QDs. Hence, CdSe/CsPbI3 QDs can serve as an interface layer to promote interfacial charge extraction and enhance light harvesting ability simultaneously. Compared with pristine perovskite solar cells (PSCs), hybrid CdSe/CsPbI3 QD incorporated PSCs achieve 21% enhancement in power conversion efficiency (PCE). The enhancement of PCE can be ascribed to the ultrafast charge carrier dynamics and Forster resonance energy transfer (FRET) effect. The design of hybrid CdSe/CsPbI3 QDs offers an alternative method for interfacial engineering to enhance optical properties and facilitate the charge transport process in PSCs.

Metal-organic frameworks (MOFs) have emerged as promising electrocatalysts due to their controllability and diversity in functional species of metal centers and organic linkers. Herein, two-dimensional (2D) bimetal-MOFs (CoxFe-MOF) nanosheets with a thickness of similar to 10 nm are synthesized and employed for OER and NRR in alkaline medium. By regulating the composition of CoxFe-MOF, the optimized Co₃Fe-MOF can achieve an overpotential of 280 mV at a current density of 10 mA cm(⁻²) with a small Tafel slope of 38 mV dec(-1) in 1.0 M KOH electrolyte, outperforming the commercial RuO₂ (351 mV at 10 mA cm(-2), 99 mV dec(-1)). The enhanced OER performance can be attributed to the abundant active centers and the positive coupling effect between Co and Fe metal ions in the MOF. Additionally, the NRR performance of the obtained Co₃Fe-MOF is evaluated on glassy carbon electrode to achieve real NH₃ faradaic efficiencies (FE) and NH₃ yield rates. The Co₃Fe-MOF delivers a FE up to 25.64% with the corresponding NH₃ yield rate of 8.79 mu g h(-1) mg(cat)(-1) at -0.2 V versus the reversible hydrogen electrode (vs. RHE) in 0.1 M KOH electrolyte. The results indicate the potential application of 2D MOFs in NRR and provide the rational design of efficient electrocatalysts for coupling both OER and NRR in a full-cell configuration. Ministry of Education (MOE) National Research Foundation (NRF) This work was financially supported by Singapore MOE AcRF Tier 2 under Grant No. 2018-T2-01-010, National Research Foundation of Singapore (NRF) Investigatorship, Award Number NRF2016NRF-NRFI001-22 and the China Scholarship Council (201808420125). The authors thank the Facility for Analysis, Characterization, Testing and Simulation (FACTS) of Nanyang Technological University, Singapore, for technical support and the 111 Project (D18023) from Zhengzhou University.

The development of ultraviolet to near-infrared (UV-Vis-NIR) responsive photocatalysts offers a unique opportunity for the full use of solar energy to solve the energy and the environmental problems. Here, successful preparation of a three-dimensional (3D) porous photocatalyst of graphitic carbon nitride quantum dot (CNQDs) modified g-C3N4/graphene oxide composite aerogel (CNGO/CNQDs) via hydrothermal and vacuum injection method was reported. In this unique ternary 3D photocatalyst, graphene oxide could improve the separation of photogenerated electrons and holes and promote the charge separation, while the aerogel's 3D network structure provided a rich active site. Simultaneously, due to the appropriate up-conversion performance of the nitrogen carbide quantum dots, CNGO/CNQDs achieved a light response from ultraviolet (UV) to near-infrared (NIR). These properties endow it with a good photocatalytic performance. The hydrogen production efficiency of CNGO/CNQDs reached 1231 μmol h−1, which was 16 times more than that of matrix material. In addition, the apparent quantum yields (AQY) of CNGO/CNQDs at wavelengths of 420 nm and 700 nm were 13% and 0.116%, respectively.

As newly-developing non-noble metallic co-catalysts, MXenes have attracted intensive attention as an ideal candidate to promote the photocatalytic H 2 -production activity. In this study, Ti 3 C 2 nanosheets prepared by intercalation were further attached to porous MOFs (UiO-66-NH 2 ) via one-pot hydrothermal method to form face-to-face intimate contact. The obtained TU10 presented the highest photocatalytic H 2 -evolution rates in TU series, exceeding that of pure UiO-66-NH 2 by approximately 8 times. The speculation revolving about enhanced photocatalytic H 2 -production performance was proposed as the presence of exposed active sites at the edge of Ti 3 C 2 nanosheets and spatial separation and transfer of charge carriers introduced by the Schottky junction at TU series interface, which accumulated the photo-induced electrons on the surface of Ti 3 C 2 nanosheets and improved its electron-donating ability. The DFT calculations revealed that O-terminated Ti 3 C 2 possessed the most positive Fermi level and the lowest Gibbs free energy (|ΔG H* | = 0.08 ≈ 0). This work may provide new insights for constructing MXenes/MOFs structure based on Schottky junction effect to achieve high photocatalytic H 2 -production performance.

TiO2 photoanode as the light harvest skeleton and electron transport material plays a critical role in the photovoltaic performance of the quantum dots sensitized solar cells (QDSSCs). In this paper, a bilayer-structured film with micro-flower TiO2 as an overlayer and hierarchical porous TiO2 as an underlayer is fabricated. The hierarchical porous TiO2 film is synthesized by the virtue of foam and the TiO2 micro-flower is introduced by spin-coating method. This TiO2 micro-flower supplies more adsorption sites for CdSe quantum dots, thus leading to the enhanced light harvesting efficiency. The staggered structure between the anatase nanoparticle and the rutile micro-flower will facilitate the separation of electron-hole pairs and promote the injection process of electron. Consequently, the photovoltaic performance of QDSSCs based on the TiO2 micro-flower modified photoanode is about 43% higher than that of the bare porous TiO2 photoanode.

Power conversion efficiency (PCE) of quantum dot-sensitized solar cells (QDSSCs) was boosted in a TiO2 composite film (TCSF) with delicate design in structure where TiO2 hierarchical porous film (THPF) situated on the top of TiO2 nanorod arrays film (TNAF). In this case, TNAF could supply efficient scattering centers for high light harvesting and direct electrical pathways for fast electron transfer while the THPF could offer porous channels for loading high quantity of previously synthetized quantum dots (QDs) and facilitate the penetration of electrolyte. Meanwhile, in this specific configuration, the presence of anatase–rutile heterojunction at the interface could help the rutile TNAF layer to efficiently collect photo-injected electrons from the anatase THPF layer thus suppressing the recombination of electrons and holes in electrolyte. The results showed that the PCE of QDSSC based on the TNAF photoanode was about 1.4-fold higher (η = 3.05%, Jsc = 15.86 mA cm−2, Voc = 0.602 V, FF = 0.319) than that of device based on pure THPF (η = 2.20%, Jsc = 13.82 mA cm−2, Voc = 0.572 V, FF = 0.278).

A novel three dimensional (3D) cellular network structured TiO 2 film is developed for CdS/CdSe quantum dots sensitized solar cells (QDSSCs). The vertically net-connected hollow TiO 2 photoanode is synthesized via a stepwise hydrothermal method. Benefiting from the hierarchical architecture, the specific surface area is dramatically enhanced thus allowing for loading more quantum dots. Besides, the optical characteristic results demonstrate that the light scattering ability is improved which could be ascribed to the easily trapped incident light in the cellular net-connected TiO 2 . Furthermore, the one dimensional (1D) structure inherited from nanorods arrays provides direct channels for electron transport accompanied with less recombination. The measured power conversion efficiency (PCE) of the QDSSCs based on this cellular TiO 2 photoanode is 4.54%, which is 2.2 times higher than that of the QDSSCs based on the original TiO 2 nanorods photoanode. The enhanced photovoltaic performance is ascribed to the higher light harvesting efficiency, improved light scattering property and promoted electron transport. The net-connected photoanode with 1D structure could offer the design of tailored architecture targeting various solar cells.

The annealed Ti3C2Tx MXenes retained original layered morphology and gave rise to the formation of TiO2 is anticipated to achieve improved photocatalytic hydrogen evolution performance as a noble-metal-free co-catalyst. In this work, a novel Ti3C2/TiO2/UiO-66-NH2 hybrid was rationally designed for the first time by simply introducing annealed Ti3C2Tx MXenes over water-stable Zr-MOFs (UiO-66-NH2) precursors via a facile hydrothermal process. As expected, the rationally designed Ti3C2/TiO2/UiO-66-NH2 displayed significantly improvement in photocatalytic H2 performance (1980 μmol·h−1·g−1) than pristine UiO-66-NH2 under simulated sunlight irradiation. The excellent photocatalytic HER activity can be attributed to the formation of multi-interfaces in Ti3C2/TiO2/UiO-66-NH2, including Ti3C2/TiO2/UiO-66-NH2, Ti3C2/TiO2 and Ti3C2/UiO-66-NH2 interfaces, which constructed multiple pathways at the interfaces with Schottky junctions to accelerate the separation and transfer of charge carriers and endowed the accumulation of photo-generated electrons on the surface of Ti3C2. This work expanded the possibility of porous MOFs for the development of efficient photocatalytic water splitting using annealed MXenes.

Heterojunction is considered as very promising material for various applications in photocatalysis. Herein, an efficient heterojunction photocatalyst N/Zn–TiO2@NH2-MIL-125 was successfully synthesized for photo-degradation organic oxidation by biological-templated method. The electron–hole pairs can be separated in space more efficiently because of heterojunction structure. Systematical analyses of spectroscopy and microscopy measurements revealed that N/Zn–TiO2@NH2-MIL-125 heterojunction materials exhibited hierarchical porous structure with high surface area of 366.02 m2 g−1 and outstanding optical properties. Photocatalytic activity was investigated by degradating of rhodamine B (1000 µM) under visible-light irradiation. The N/Zn–TiO2@NH2-MIL-125 showed enhanced photocatalytic activity for RhB degradation, which is respectively about 1.81 and 1.97 times higher than that of the pristine N/Zn–TiO2 and NH2-MIL-125. Various advanced spectroscopic characterizations were applied including photoluminescence, Mott–Schottky curves and electrochemical impedance spectroscopy. A possible mechanism of enhanced photocatalytic oxidation activity for N/Zn–TiO2@NH2-MIL-125 composite under visible light irradiation was discussed.

A method of fabricating a stretchable and flexible electronic device includes forming each of the functional layers is by: (i) forming on an elastomer substrate a conductive interconnect pattern having islands interconnected by bridges; (ii) applying a conductive paste to the islands; (iii) positioning at least one functional electronic component on each island; and (iv) applying heat to cause the conductive paste to reflow. An elastomer encapsulant is formed over the functional electronic components and the conductive interconnect pattern on each of the functional layers. The elastomer encapsulant has a Young's modulus equal to or less than that of the substrate. The encapsulant includes a pigment to increase absorption of laser light. At least one via is laser ablated, which provides electrical connection to any two functional layers. The via is filled with solder paste to create a bond and electrical connection between the functional layers.

The porous and water-stable polyoxometalates-based Zr-MOFs PW12@UiO-NH2 was proposed for photocatalytic H2 evolution and degradation pollutants via adopting Keggin-type polyoxometalates (POMs) into UiO-66-NH2 through a facile one-step solvothermal method. Systematically characterizations were carried out to confirm the encapsulation of Keggin-type PW12 within the cavities of porous UiO-66-NH2 without modifying its fundamental framework. Benifiting from the integration of Keggin-type PW12 units with redox activity and porous UiO-66-NH2, the results showed that enhanced photocatalytic H2 evolution performance and RhB degradation activity for PW12@UiO-NH2 were realized compared with pristine UiO-66-NH2 under visible-light irradiation. The significant improvement of photocurrent density under a monochromatic light irradiation implied the faciliated separation procedure of photo-generated charge carriers with the incorporation of Keggin-type PW12 units. Hence, our findings reveal a novel topology POM-based MOFs which paves a way for environmental and energy applications.

With increasing concern about the problems of environmental pollution and energy, the visible light photocatalytic for dye degradation is receiving considerable attention. CdSe quantum dot (CdSe QDs) sensitized MIL-125/TiO2@SiO2 biogenic hierarchical materials (CMTS) has been fabricated through dual modification of CdSe with TiO2 and MIL-125, that is the metal–organic framework (MOF) with Ti ions as metal centers and terephthalic acid as the organic ligand. The hierarchical porous heterostructured MIL-125/TiO2@SiO2 composites are firstly obtained by a biogenic-templated method using rice husk as biomorphic. CdSe QDs as sensitizer is further deposited on MIL-125/TiO2@SiO2 via a dipping method. This strategy applies CdSe, MIL-125, and TiO2 undergo a two-level heterostructure, setting a stage for efficient charge separation. In addition, CMTS possesses a hierarchical porous structure in scale from micrometer to nanometer with high BET surface area. As a result, the CMTS can efficiently adsorption target, improving light harvesting and promoting degradation of organic waste from water. Meanwhile, Rhodamine B aqueous solution can be degraded more than 98% by CMTS in 100 min under visible light irradiation.

One-dimensional/three-dimensional (1D/3D) hierarchical porous network configurations are composed of NiCo2S4 nanowires in-situ grown on biomass carbon (NiCo2S4/3DHC). The 3D biomass carbon (3DHC) with hierarchical micron- to nano-porous structure which is suitable for as a basal growth has been obtained from a pyrolysis active process of wood (Metasequoia). NiCo2S4 nanowires were produced on 3D biomass carbon via a facile hydrothermal method. The characterization and comparison of various properties of NiCo2S4/3DHC have been investigated systematically. A maximum specific capacitance of 765.8 F/g was observed for the NiCo2S4/3DHC electrode at 1 A/g in a 6 M KOH electrolyte solution, while 32.3 F/g for 3DHC at the same condition. The method reported here can be potentially applied to feasible construct 3D electrode configuration for energy storage devices using biomass as main raw materials.

A hybrid photocatalyst consisting of TiO2 and nonporous SiO2 (TiO2/CS-RH) is prepared by loading TiO2 sol on one-dimensional/three-dimensional chain (1D/3D-chain) which is synthesized from rice husk. The products are characterized by X-ray diffraction, N2-adsorption–desorption analysis and scanning electron microscopy. Meanwhile, the corresponding photocatalytic activity is evaluated by measuring the photocatalytic oxidation of rhodamine B (RhB). The results reveal that TiO2/CS-RH displays a hierarchical porous structure from micrometer to nanometer scale with high BET surface area (574.7–719.4 cm2/g). Meanwhile, the activity of TiO2/CS-RH for the photocatalytic degradation of RhB in aqueous slurry is significantly higher than that of the unsupported TiO2. The optimal TiO2 loaded on the support was two times and then treated at 600 °C for 120 min to complete the conversion of RhB. In contrast, the unsupported TiO2 photocatalyst could convert only 20% of RhB in the same irradiation time and condition.

The fabrication of low-cost and environmentally friendly photocatalysts with superior photodegradation efficiency remains one of the most pressing challenges in present research. Herein, we elaborately designed and synthesized a promising N-doped carbon quantum dots/CeO2 hollow microsphere (NCQDs/h-CeO2) photocatalyst with superior photoresponse property and photoactivity in visible light. The removal efficiencies of rhodamine B (RhB) under visible light illumination for NCQDs/h-CeO2 exhibits a 30.3% enhancement compared with pure h-CeO2. The results of EIS and PL imply that the excellent performance may be attributed to the strong synergistic effect between NCQDs and h-CeO2, thus effectively promoting charge transfer and restraining the recombination of photogenerated holes and electrons. Accordingly, a synergistic photocatalysis mechanism was proposed to explain the photocatalytic reaction process. Besides, the NCQDs/h-CeO2 exhibits better cycle stability than common CQDs/h-CeO2 after a four-cycle photocatalytic test. Therefore, the NCQDs/h-CeO2 may represent a promising strategy for the current water pollution issues.

In this work, PbI2 is coated on the TiO2 films via the cost-effective electrochemical deposition method and a MAPbI3 layer is formed by exposing the deposited PbI2 to CH3NH3I subsequently. The structure, composition and morphology of the deposits are characterized in detail by the measurements of X-ray diffraction, scanning electron microscopy, and energy dispersion spectroscopy, respectively. The results suggest that a high coverage and uniform perovskite layer has been fabricated by virtue of the electrochemical deposition method. The influence of the deposition time in the morphology of the obtained perovskite is investigated and the optical properties of the prepared PbI2 and CH3NH3PbI3 are studied as well. As a result, the assembled perovskite solar cells exhibited a maximum PCE of 6.62% with the corresponding photocurrent of 12.5 mA cm−2 and open-circuit voltage of 0.957 V at AM 1.5 solar light of 100 mW cm−2, thus demonstrating the feasible application of electrochemical deposition in perovskite solar cells.

A finite deformation mechanism-based thermodynamically consistent constitutive framework is presented for describing the dynamic behaviors of brittle materials under impact loading. The framework is developed based upon a multiplicative decomposition of the deformation gradient in terms of multiple mechanisms, including recoverable elasticity, crack-induced damage, and other inelastic mechanisms such as subgrain and granular plasticity. The finite deformation kinematics that captures the multiple mechanisms is structured within a thermodynamically consistent framework, and the consequent coupling of the various mechanisms is articulated. Specific constitutive equations are formulated for a Mie–Gruneisen equation of state, micromechanics-based dynamic-fracture-induced damage growth, subgrain or lattice plasticity for slip and other deformation modes, and granular plasticity for granular flow and pore collapse post-fragmentation. Using hot-pressed silicon carbide (SiC-N) as the model material, this integrative model is calibrated using available experiments that interrogate specific mechanisms. The effects of loading rate, the influence of confinement, and the path-dependent constitutive behaviors of the material predicted by the model are demonstrated. The model performance at the application scale is then evaluated by simulating previously performed sphere-on-cylinder impact experiments.

A novel Bibendum-like structure of g-C3N4 microtubes (HCN-5) regularly arranged by nanotubes is synthesized for the first time via surfactant induction, and a plausible mechanism for the formation of HCN-5 is proposed. The formation of nanotubes not only provides a convenient way for charge transport but also promotes the enrichment of photogenerated electrons in the active site. The regular arrangement effectively prevents the agglomeration of the nanotubes. These make the photocatalytic water-splitting hydrogen production rate of HCN-5 more than 14 times that of bulk g-C 3N4, reaching 169.6 μmol/h. And, the AQY for H2 evolution reaches 13.1% at 380 nm. The mechanism of improving photocatalytic hydrogen production efficiency and the carrier transfer path is described through DFT calculation.

In this paper, we propose a novel Fe-based polyoxometalates @ metal–organic framework (POM@MOF(Fe)) material synthesized by a one-step solvothermal strategy to combine the merits of adjustable structure of MOFs and excellent electrochemistry properties of POMs. Fe ions are connected by organic linkers 1,4-H2BDC and 4,4′-bipyridine to build frameworks and combined with Keggin-type H3PW12O40 units inside. A leaf-like structure of POM@MOF(Fe) crystals are obtained which exhibits good optical response in visible range with absorption edge at around 750 nm. Herein, we describe the assembly and characterization of a simplified solar cell based on POM@MOF(Fe) crystals modified the ZnO photoanode. The photovoltaic performance of solar cells with POM@MOF(Fe) modified the ZnO as photoanode without any sensitizer is enhanced compared to the bare ZnO which is clearly ascribed to the POM@MOF(Fe). The results demonstrate that this novel composite of POM@MOF(Fe) is a good electron–hole separation materials thus benefiting the photovoltaic property of ZnO. Hence, solar cells based on this novel photoanode can be expected to exhibit good photovoltaic performance.

Three-dimensional (3D) architectures assembling with Zn2SiO4 nanowires were synthesized by a novel molten-salt method using rice husk both as biomorphic template and SiO2 source. Also, ZnCl2 powder was chosen as reactant and molten-salt. X-ray diffraction, scanning electron microscope and transmission electron microscope were used to investigate the morphology and composition of this unique architecture. Nitrogen adsorption measurements verified the presence of mesoporous structure. The growth process of the synthesized Zn2SiO4 nanowires was proposed, including the introduction of ZnCl2 to rice husk, the formation of ZnOCl2·H2O nanostructures, and the growth of 3D Zn2SiO4 textured nanowires. Furthermore, the absorption capacity of 3D Zn2SiO4 architectures to remove Fe3+, Cr3+ and Mg2+ in water was performed.

Large quantities of hexagonal boron nitride (h-BN) nanotubes (BNNTs) with high purity have been successfully synthesized under ammonia gas flow at 1200 °C via catalytic pyrolysis of organic-inorganic hybrid precursor which was pre-prepared through a wet chemistry method at 95 °C. Several characterizations, such as SEM, TEM, XRD, FTIR, EDS, XPS and SAED measurements, were used to confirm the morphology, composition and crystalline structure of the as-synthesized powders. It was observed that the obtained product was a kind of nanotubes (NTs) in hexagonal BN phase with a curved shape and smooth surface. The diameter of BNNTs was distributed in a range of 60–200 nm while its length was about tens of microns. The possible growth mechanism of BNNTs was also proposed in this paper.

The present work demonstrates the effect of Mn, Fe, Ni and Cu doping on the orientation, microstructure, electrical and thermal transport properties of Bi 0.5 Sb 1.5 Te 3 ingots prepared under a 2 T magnetic field. The comparative results show that the c-axis is inclined to perpendicular to magnetic field in the ferromagnetic ions (Fe and Ni) doped samples, while is inclined to parallel to magnetic field in the non-magnetic Cu and paramagnetic Mn doped samples; in addition, the growth of eutectic structure is disturbed intensively in the ferromagnetic ions doped samples, resulting in scattered arrangement of Te trips, BST Ⅱ nano-rods and nano-scale Te crystals. As a consequence, the thermal conductivity in the ferromagnetic ions doped samples are sharply decreased owing to the enhanced scattering of holes and phonons by the hierarchical architecture of phase boundaries, grain boundaries, BST Ⅱ nano-rods even sub-grain boundaries, and a high ZT of ∼1.6 at 323 K was obtained in the ferromagnetic ions doped samples.

Ultra-stable foams with multilayer films which were similar to the structure of colloidal gas aphrons (CGA) were designed in view of increasing the amount of bound water molecules at molecular level. This liquid films in foams were spontaneously assembled by 1-dodecanol (DDA), sodium dodecyl sulfonate (SDS) and polyvinyl alcohol (PVA) molecular with a remarkable long-term foam lifetime. The states of water molecules as well as the molecular arrangement in foam films have been analyzed via molecular dynamics (MD) simulation to explore microscopic character and stable mechanism of multilayer films of foams. We found that the combined effect of SDS, DDA and PVA could not only increase distribution intensity of bound water molecules in foam film layers, but it also could decrease the gas diffusion rate to balance the pressure of the air layers of the multilayer foams.

Developing high thermoelectric performance CuInTe 2 based materials is technologically and environmentally intriguing, in order to achieve this, nanoscale heterostructure barrier blocking is proposed and adopted in this work by directly incorporating excess ZnX (X=S, Se) to regulate the electrical and thermal transport properties of CuInTe 2 . The results prove that part of the ZnX dissolves into the CuInTe 2 matrix during the hot press process while the residual ZnX acts as a nanoscale heterostructure barrier blocking for both the hole and phonon. As a consequence, three thermoelectric parameters of the CuInTe 2 have been optimized simultaneously by this approach, owing to the formation of Zn- In point defects to improve carrier concentration, the concurrent hindering to the minority carriers resulting from the energy level difference between matrix and nano-heterostructure to enhance the Seebeck coefficient, and intensive phonon scattering by the nanoscale heterostructure barrier blocking to reduce the thermal conductivity. Eventually, a 90% enhanced ZT value of 1.52 has been obtained in the 6 wt% ZnS added CuInTe 2 sample.

By means of electrochemical atomic layer deposition (ECALD), cobalt selenide counter electrodes have been successfully prepared on FTO substrate for the first time. The as-grown films presented amorphous structure and their composition and microstructure could be regulated effectively by adjusting the depositing potential of Se via the route of ECALD. Cycle voltammograms and Tafel polarization measurements revealed that the cobalt selenide counter electrode exhibited an excellent catalytic activity and stability in the I−/I3− system. Due to the more active catalytic sites and less charge-transfer resistance, the Co1.2Se counter electrode yielded faster and more complete reduction of I3− to I− than the Pt and other compositions of cobalt selenide. As a result, the dye-sensitized solar cell based on the Co1.2Se counter electrode yielded a photoconversion efficiency of 9.28%, which improved by 136% than that of the DSSC based on the Pt electrode (6.84%). Taking the facility and cost efficiency into consideration, ECALD has great potential in preparing high efficient counter electrode for high performance DSSCs.

Efficient charge transfer with suppressed charge recombination is crucial for perovskite solar cells (PSCs) with high photovoltaic performance. Herein, Ti3C2 quantum dots (QDs) are introduced into the perovskite layer, and Ti3C2 nanosheets are inserted into the TiO2 electron transport layer (ETL). The results confirm that the incorporation of Ti3C2 QDs can effectively reduce the defect state concentration of perovskite films, and the Ti3C2 nanosheets can improve the electron mobility of the ETL. By taking advantages of zero- and two-dimensional Ti3C2, the performance of PSC achieves an enhancement of photoelectric conversion efficiency from 12.0% to 17.1%, along with reduced hysteresis effect of the device. This article explores a promising strategy to exploit MXenes in the application of PSCs.

It reported a novel and simple method for the first time to prepare TiO 2 hierarchical porous film (THPF) using ultrastable foams as a soft template to construct porous structures. Moreover, dodecanol as one foam component was creatively used as solvent during the synthesis of CdSe quantum dots (QDs) to decrease reaction temperature and simplify precipitation process. The result showed that hierarchical pores in scale of microns introduced by foams were regarded to benefit for high coverage and unimodal distribution of QDs on the surface of THPF to increase the efficiencies of light-harvesting, charge-collection and charge-transfer. The increased efficiencies caused an enhancement in quantum efficiency of the cell and thus remarkably increased the short circuit current density ( J sc ). In addition, the decrease of charge recombination resulted in the increase of the open circuit voltage ( V oc ) as well. The QDSSC based on THPF exhibited about 2-fold higher power conversion efficiency ( η = 2.20%, J sc = 13.82 mA cm −2 , V oc = 0.572 V) than that of TiO 2 nanoparticles film (TNF) ( η = 1.06%, J sc = 6.70 mA cm −2 , V oc = 0.505 V). It provided a basis to use foams both as soft template and carrier to realize simultaneously construction and in-situ sensitization of photoanode in further work.

By dipping the mesoporous TiO 2 film in Sr 2+ solutions and subsequent annealing, a modification layer of SrTiO 3 has been formed on the surface of the mesoporous TiO 2 film, and the effect of modification on the photovoltaic characteristics of the perovskite solar cells has been studied detailedly. The XPS and TEM results verified the existence and nature of the SrTiO 3 modification layer. Benifiting from the TiO 2 surface modification, the morphology of perovskite film and light absorption of the CH 3 NH 3 PbI 3 absorber have been improved effectively, and a faster charge transfer has also been achieved between the CH 3 NH 3 PbI 3 perovskite layer and the modified TiO 2 . As a result, an average conversion efficiency of 11.4% has been achieved in the perovskite solar cell based on the modified mesoporous TiO 2 by 10 mM Sr 2+ solution, and it increases approximately by 46% in comparison with the photovoltaic efficiency of 7.8% of the perovskite solar cell based the bare mesoporous TiO 2 layer.

With Al foil, Cu foil and steel mesh as the metal interlayers, respectively, three types of alumina/epoxy/metal laminated composites were fabricated with epoxy resin adhesive as a binder via a simple process. The impact tests were performed and the fracture patterns and impact response of all the three laminates were analyzed. The experimental results indicate that the absorbed energy is mainly determined by metal interlayer. The peak load depends on not only alumina substrate but also metal interlayer. The Al2O3/epoxy/Cu laminates sustain the maximum peak load and Al2O3/epoxy/steel mesh laminates have the largest threshold energy for penetration. The fracture analysis shows that the main damage modes are Al2O3 matrix cracking and metal deformation for lower impact energies, and complete breakage and penetration for higher impact energies.

Given the thermoelectric and mechanical performance of a given material is closely related to its microstructure, in this paper, the microstructure of p-type Bi 0.5 Sb 1.5 Te 3 , fabricated by a high magnetic field assisted melting-solidification (HMAMS) process, is successfully tuned by regulating the cooling rate during the solidification process, and a systematic investigation has been carried out to the effect of the cooling rate on the crystal orientation, microstructure, thermoelectric and mechanical performance of the obtained materials. By this approach, the thermal conductivity is sharply reduced due to the intensive phonon scattering by the massive BST/Te and Te/BST Ⅱ interfaces, while the power factor is less affected, and the flexural strength is enhanced owing to the narrowing of eutectic strip and spacing. Eventually, a highest ZT of 1.23 at 323 K with a maximal flexural strength 23.2 MPa has been obtained in the sample prepared under a 6 T magnetic field at a cooling rate of 16 K/min.

In this paper, a hybrid generator has been fabricated by connecting a dye sensitized solar cell (DSSC) with a single p–n junction thermoelectric generator (TEG) in series. Both the open-circuit voltage and the short circuit current of the hybrid generator have been enhanced obviously in comparison with the algebraic sum of those of the DSSC and TEG. The increase of non-equilibrium carrier concentration originates from the synergistic effect between the TEG and DSSC, which lifts the quasi-Fermi energy level and improve the photoelectric response rate thus enhancing the open-circuit voltage and current density of the DSSC. As a result, a conversion efficiency of 9.08% has been obtained in hybrid B, which is greatly enhanced by 20.6% and 725.5% in comparison with that of the separate DSSC and TEG, respectively.

In this study, high coverage and uniformly distributed Bi 2 S 3 and Sb 2 S 3 quantum dots (QDs) are deposited simultaneously on the surface of TiO 2 nanorods (NRs) via electrochemical atomic layer deposition (ECALD) method. The structure, morphology and composition of the deposits are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersion spectroscopy analysis (EDS), respectively. The results show that the deposits are of Bi 2 S 3 and Sb 2 S 3 compound semiconductor, and the Bi 2 S 3 /Sb 2 S 3 QDs cover on the top and side surface of TiO 2 NRs homogeneously. EDS analysis demonstrates that the ratio of both S to Sb and S to Bi are approximately 3:2, indicating that ECALD method can well control the deposition of each element. Owing to the better light absorption property and reduced recombination possibility of Bi 2 S 3 /Sb 2 S 3 QDs co-sensitized solar cells, the power conversion efficiency reaches 0.67% with a short-circuit current density of 4.83 mA cm −2 at AM 1.5 solar light of 100 mW cm −2 , which is much higher than that of Bi 2 S 3 or Sb 2 S 3 QDs sensitized solar cells.

Dynamic point impact loading is a primary cause of fracture of glass screens on mobile devices. An improved understanding of crack initiation and evolution under high-speed indentation could contribute to the development of materials with better performance, but experimental observations are challenging due to the short timescales and limited depth-of-field of optical microscopy. To address this need, we have observed fracture of a chemically-strengthened glass during dynamic indentation using in situ x-ray phase-contrast imaging (XPCI). Median cracks initiate below the surface of the glass, at a depth approximately corresponding to the depth at which the surface residual compressive stress diminishes to zero. These cracks initially propagate at ∼ 10 m s − 1 , rapidly accelerating to > 100 m s − 1 . We also observe some evidence for rate-dependent behavior, in that indentation at the lowest rates studied here (below about ∼ 0 . 15 m s − 1 ) fails to initiate cracks regardless of the depth of the indentation (up to 18 μ m ), while indentation at higher rates produces median cracks that either arrest or cause complete fracture, depending on the depth of indentation.

In this work, graphene aerogel/carbon foam is prepared by in situ inducing graphene aerogels in the pores of carbon foam. This novel hierarchical porous structure possesses a higher specific surface area as the introduction of graphene aerogels in carbon foam increases the proportion of micropores thus making it a superior candidate as electrodes for supercapacitors. The characterization and comparison of various properties of carbon foam and graphene aerogels/carbon foam have been investigated systematically. The result shows that specific surface area is up to 682.8 m2/g compared with initial carbon foam which increased about 55%, and the pore distribution curve shows more pore volume at 0.3 nm for F-CF/GA. It is demonstrated that the introduction of graphene aerogels not only increases the specific surface area, but also improves the conductivity, thus resulting in the reduction of the internal resistance and the improvement of the electrochemical performance. Consequently, graphene aerogel/carbon foam shows an excellent specific capacitance of 193.1 F/g at 1 A/g which is 72% higher than that of carbon foam acted as electrodes for supercapacitors.

Constructing heterojunction is usually considered as an efficient strategy to promote efficient charge separation in photo-electrochemical/catalyst system. Herein, Fe2O3-MIL-101 heterojunction film is built by covering one MIL-101 layer on Fe2O3 nanoclusters via one-drop method under hydrothermal condition. The morphology, structure and photo-electrochemical performance of layered Fe2O3/MIL-101 heterojunction film are systematically studied. The results show the construction of type-Ⅱ heterojunction is favorable to high separation efficiency of photogenerated carriers and accelerated water oxidation process on the surface of MIL-101 which are demonstrated by the improved photocurrent density and weakened electrochemical polarization.

Static and dynamic analysis of the fracture tests of fiber composites in hydraulically servo-controlled testing machines currently in use shows that their grips are much too soft and light for observing the postpeak softening. Based on static analysis based on the second law of thermodynamics, confirmed by dynamic analysis of the test setup as an open system, far stiffer and heavier grips are proposed. Tests of compact-tension fracture specimens of woven carbon-epoxy laminates prove this theoretical conclusion. Sufficiently, stiff grips allow observation of a stable postpeak softening, even under load-point displacement control. Dynamic analysis of the test setup as a closed system with proportional-integrative-differential (PID)-controlled input further indicates that the controllability of postpeak softening under crack-mouth opening displacement (CMOD) control is improved not only by increasing the grip stiffness but also by increasing the grip mass. The fracture energy deduced from the area under the measured complete load-deflection curve with stable postpeak is shown to agree with the fracture energy deduced from the size effect tests of the same composite, but the size effect tests also provide the material characteristic length of quasibrittle (or cohesive) fracture mechanics. Previous suspicions of dynamic snapback in the testing of stiff specimens of composites are dispelled. Finally, the results show the stress- or strain-based failure criteria for fiber composites to be incorrect, and fracture mechanics, of the quasibrittle type, to be perfectly applicable.