Photocatalysis is considered to be one of the possible routes to solve energy crises at a low cost. Graphitic-C
3
N
4
combined with other semiconductors at the nanoscale has demonstrated a promising ...potential in photocatalysis application owing to the heterojunction configuration. In this study, Ag/g-C
3
N
4
/CuNb
2
O
6
-4 (mass ratio of CuNb
2
O
6
to g-C
3
N
4
= 1:4) composites were prepared by photo-deposition of Ag particles on the hydrothermally synthesized g-C
3
N
4
/CuNb
2
O
6
-4 composites. The microstructure, morphology, and light absorption property of the photocatalysts were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–Vis diffuse reflectance spectroscopy. The photocatalytic properties of photocatalysts and active species responsible for the degradation of RhB dye under visible light were investigated. After loading Ag particles on the g-C
3
N
4
/CuNb
2
O
6
-4 composites, the resulting Ag/g-C
3
N
4
/CuNb
2
O
6
-4 composites show a bandgap of ~ 2.31 eV and a significant increase in photocatalytic efficiency. In particular, the photocatalytic activity of 11% Ag/g-C
3
N
4
/CuNb
2
O
6
-4 composite (Ag mass fraction = 11%) is nearly seven times that of orthorhombic CuNb
2
O
6
and 3.8 times that of g-C
3
N
4
/CNO-4 composite. The Z-scheme heterojunction has been successfully formed in the Ag/g-C
3
N
4
/CuNb
2
O
6
-4 composites and it enhances the photocatalytic performance significantly with the best degradation efficiency of 88% after 2 h.
Electroless nickel composite coatings have the potential for high-temperature tribological applications, and a combination of high wear resistance and low friction factor is one of the desirable ...solutions but still a tricky problem. The addition of self-lubricating WS2 and hard Si3N4 nanoparticles to the Ni-P coatings is expected to obtain good high-temperature tribological performance. In this work, Ni-P-Si3N4-WS2 composite coatings with various contents of WS2 nanoparticles were prepared using electroless plating and subsequently annealed at 400 °C in an inert atmosphere. The tribological properties of the coatings were evaluated using a ball-on-disc wear instrument at operating temperatures from 25 to 600 °C. The microstructure, chemical composition, and surface morphology of the coatings were characterized by X-ray diffractometry (XRD), energy disperse spectroscopy (EDS), and scanning electron microscopy (SEM). Upon increasing the WS2 dosage in the bath, the WS2 content in the coating increased and the micro-hardness of the as-plated coating increased from 539 to 717 HV. After heat treatment, the coating underwent a crystallization process, and the hardness increased from 878 to 1094 HV. The main wear mechanism of the coating changed from adhesive wear in the as-plated state to abrasive wear in the annealed state. The annealed Ni-P-Si3N4-WS2 coating with a WS2 dosage of 2.5 g/L in the bath exhibited excellent mechanical properties, with a hardness of 10.9 GPa, a friction coefficient of ~0.51, and a wear rate of 8.4 × 10−15 m3N−1⋅m−1 at room temperature, and maintained optimal performance at high temperatures. At operating temperatures of 200, 400, and 600 °C, the form of wear was adhesive wear for coatings with a WS2 dosage <1.5 g/L and abrasive wear for coatings with a WS2 dosage ≥1.5 g/L. The synergism of WS2 and Si3N4 particles refined the grains of the Ni-P matrix in as-plated coatings and obviously reduced the friction coefficient of friction pairs in annealed coatings at all operating temperatures.
Yttria-stabilized zirconia monoliths with well-defined macropores and high porosity have been successfully fabricated via sol–gel process accompanied by phase separation. Propylene oxide acts as an ...acid consumer to mediate sol–gel process, and poly (ethylene oxide) is used to induce phase separation. Ethylene glycol is applied as chelating agent, and formamide serves as drying control chemical additive to inhibit cracking during drying stage. Proper proportion of the starting compositions allows the generation of well-defined macroporous YSZ monoliths with co-continuous skeletons and porosity as high as more than 60 %. The dried gels are amorphous and crystalline of ZrO
2
precipitates after heat treatment between 400 and 1200 °C without formation of monoclinic ZrO
2
, which indicating a wide application prospects.
Ag/Bi
2
Sn
2
O
7
materials have high electrical conductivity but mechanical properties similar to those of Ag/SnO
2
owing to their poor Ag/Bi
2
Sn
2
O
7
interfacial wettability. In this study, ...Ni-doped Ag/Bi
2
Sn
2
O
7
was prepared by high-energy ball milling, powder metallurgy, and extrusion. The microstructures and physical, mechanical, and electrical properties of Ag/Bi
2
Sn
2
O
7
(Ni-doped) materials with different Ni molar fractions were investigated by XRD, SEM, XPS, Hall-effect tests, metal resistivity measurements, tensile tests, and electrical life tests. The formation of a crystalline Ni-containing solid solution is also confirmed. With an increase in the Ni-doping molar fraction from 0 to 8.3%, the resistivity of the Ni-doped Bi
2
Sn
2
O
7
powder increased, the Ag/Bi
2
Sn
2
O
7
interfacial wetting angle decreased from 104.6°, to 83.1°, the hardness and density of the Ag/Bi
2
Sn
2
O
7
(Ni-doped) material first increased and then decreased, while the resistivity exhibited an opposite tendency. The Ag/Bi
2
Sn
2
O
7
–5.2Ni (sheets) exhibited the lowest resistivity of 2.00 µΩ·cm, the highest hardness of 687 MPa, and the highest density of 9.99 g/cm
3
; its electrical life was 1.6 and 1.8 times that of Ag/Bi
2
Sn
2
O
7
and Ag/SnO
2
, respectively. Thus, an appropriate amount of Ni-doping can improve the interfacial wettability, physical properties, and electrical properties of Ag/Bi
2
Sn
2
O
7
electrical contact materials.
Photocatalysis is a green approach to solving energy and environmental problems, and researchers are still pursuing high-performance photocatalysts. Although BiOX (X = Cl or Br) has a suitable ...bandgap and good stability, its photoresponse is mostly concentrated in the UV region. Conversely, SnS2 has a wide photoresponse range but exhibits perceptible photocorrosion and poor stability. To exploit the advantages of both BiOX and SnS2, this study hydrothermally synthesized and introduced superfine SnS2 (∼30 nm in size) into a BiOCl/BiOBr binary system to fabricate BiOCl/BiOBr/SnS2 composites. Subsequently, the degradation performance of these composites in a Rhodamine B solution under visible light was investigated. Results show that the BiOCl/BiOBr/SnS2 heterojunctions were successfully prepared and the composites exhibited the best photocatalytic performance with 6% mass fraction of SnS2 (BiOCl-to-BiOBr mol ratio = 1:1). The formation of a double S-schedule heterojunction between BiOCl/BiOBr and SnS2 not only accelerated charge separation and transfer but also broadened the photoresponse range and reduced photoelectron–hole recombination under full-spectrum irradiation. Loading a small narrow-bandgap photocatalyst onto a large photocatalyst provides an effective way to construct heterojunctions with excellent photocatalytic performance. The ternary photocatalyst presents a favorable photocatalytic stability, and its photodegradation rate is 4.6, 4.5 and 220.5 times that of BiOCl, BiOBr and SnS2, respectively.
•SnS2 particles with wide photoresponse range and fine size were synthesized.•BiOCl, BiOBr and SnS2 form visible-light responsive S-type heterojunctions.•Small SnS2 shortens electron transport paths in the ternary heterojunction.•Double S-scheme greatly improves photocatalytic performance of the heterojunctions.
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•g-C3N4/Ag2MoO4/AgBr heterojunction was prepared using a facile process.•The catalyst showed effective degradations of RhB and TCH under visible-light.•More effective charge ...separation was achieved via the ternary heterojunction.•A possible dual Z-scheme mechanism of photocatalytic degradation was proposed.
Recently, the photocatalytic degradation of organic pollutants has gained increasing attention because of its high efficiency and lack of secondary pollution; however, problems such as rapid electron–hole recombination affect its degradation efficiency. In this study, a novel dual Z-scheme g-C3N4/Ag2MoO4/AgBr heterojunction was successfully prepared using a one-step room-temperature precipitation method, with its photocatalytic activity evaluated by degrading rhodamine B (RhB) and tetracycline hydrochloride (TCH). The composition and surface morphology of the ternary catalysts—characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) tests, and X-ray photoelectron spectroscopy (XPS)—confirmed the successful loading of Ag2MoO4 and AgBr onto g-C3N4. Catalytic degradation results showed that the ternary catalyst exhibited the best performance at a 40 % mass fraction of AgBr. Moreover, the ultraviolet–visible diffuse reflectance spectra (UV–Vis DRS), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), and transient photocurrent response test results show that the ternary catalyst has excellent optical properties. In addition, the significant improvement in the catalytic performance can be attributed to the effective charge separation of the dual Z-scheme photocatalytic mechanism based on radical trapping experiments, electron spin resonance (ESR) analysis, and energy band analysis. Hence, this study provides a new approach to studying more efficient photocatalysts.
Slow strain rate testing （SSRT） was employed to study the stress corrosion cracking （SCC） behavior of ZE41 magnesium alloy in 0.01 M NaCl solution. Smooth tensile specimens with different thicknesses ...were strained dynamically in both longitudinal and transverse direction under permanent immersions at a strain rate of 10-6 s-1. It is found that ZE41 magnesium alloy is susceptible to SCC in 0.01 M NaCl solution. The SCC susceptibility of the thinner specimen is lower than that of the thicker specimen. Also, the longitudinal specimens are slightly more susceptible to SCC than the transverse specimens. The SCC mechanism of magnesium alloy is attributed to the combination of anodic dissolution with hydrogen embrittlement.
Electroless nickel composite coatings have the potential for high-temperature tribological applications, and a combination of high wear resistance and low friction factor is one of the desirable ...solutions but still a tricky problem. The addition of self-lubricating WSsub.2 and hard Sisub.3Nsub.4 nanoparticles to the Ni-P coatings is expected to obtain good high-temperature tribological performance. In this work, Ni-P-Sisub.3Nsub.4-WSsub.2 composite coatings with various contents of WSsub.2 nanoparticles were prepared using electroless plating and subsequently annealed at 400 °C in an inert atmosphere. The tribological properties of the coatings were evaluated using a ball-on-disc wear instrument at operating temperatures from 25 to 600 °C. The microstructure, chemical composition, and surface morphology of the coatings were characterized by X-ray diffractometry (XRD), energy disperse spectroscopy (EDS), and scanning electron microscopy (SEM). Upon increasing the WSsub.2 dosage in the bath, the WSsub.2 content in the coating increased and the micro-hardness of the as-plated coating increased from 539 to 717 HV. After heat treatment, the coating underwent a crystallization process, and the hardness increased from 878 to 1094 HV. The main wear mechanism of the coating changed from adhesive wear in the as-plated state to abrasive wear in the annealed state. The annealed Ni-P-Sisub.3Nsub.4-WSsub.2 coating with a WSsub.2 dosage of 2.5 g/L in the bath exhibited excellent mechanical properties, with a hardness of 10.9 GPa, a friction coefficient of ~0.51, and a wear rate of 8.4 × 10sup.−15 msup.3Nsup.−1⋅msup.−1 at room temperature, and maintained optimal performance at high temperatures. At operating temperatures of 200, 400, and 600 °C, the form of wear was adhesive wear for coatings with a WSsub.2 dosage <1.5 g/L and abrasive wear for coatings with a WSsub.2 dosage ≥1.5 g/L. The synergism of WSsub.2 and Sisub.3Nsub.4 particles refined the grains of the Ni-P matrix in as-plated coatings and obviously reduced the friction coefficient of friction pairs in annealed coatings at all operating temperatures.
Establishing a definitive diagnosis of malignancy in prostate needle biopsies with very small foci of adenocarcinoma is a major diagnostic challenge for surgical pathologists. A positive diagnostic ...marker specific for prostatic adenocarcinoma may enhance our ability to detect limited prostate cancer and reduce errors in diagnosis. P504S, also known as alpha-methylacyl-CoA racemase, recently identified by cDNA subtraction and microarray technology, might serve as such a specific marker because it has been demonstrated to be highly expressed in prostatic adenocarcinoma, but not in benign prostatic glands. However, whether small foci of carcinoma can be reliably detected by this marker is a crucial question for its clinical application. The aim of this study was to assess the utility of P504S immunohistochemistry in detecting small amounts of prostate cancer in prostate needle biopsies. A total of 142 prostate needle biopsies, including 73 cases with a small focus of prostatic adenocarcinoma (</=1 mm) and 69 benign prostates, were examined by using immunohistochemistry for P504S and high molecular weight cytokeratin (34betaE12). P504S immunoreactivity was found in 69 of 73 cases (94.5%) of carcinoma but not in any benign prostates (0 of 69) or benign glands adjacent to malignant glands. The 34betaE12 immunostaining confirmed the absence of basal cells in the focus of carcinoma in all 73 cases. The high specificity and sensitivity of P504S in the detection of minimal prostatic adenocarcinoma indicated its potential diagnostic value in clinical practice. Using a combination of P504S and 34betaE12 can help the diagnosis of limited prostatic adenocarcinoma on needle biopsy.
