The objective of this research is to prepare specially designed surface texture on hard steel surface by electrochemical micromachining (EM) and to incorporate electroless plated Ag/MoS2 solid lubricant coating into t...The objective of this research is to prepare specially designed surface texture on hard steel surface by electrochemical micromachining (EM) and to incorporate electroless plated Ag/MoS2 solid lubricant coating into the dimples of EM textured steel surface to effectively reduce friction and wear of steel-steel contacts. The friction and wear behavior of the Ag/MoS2 solid lubricant coating on EM textured steel surface was evaluated in relation to the size and spacing of the dimples thereon. The microstructure of as-plated Ag/MoS2 solid lubricant coating and the morphology and elemental composition of the worn coating surface and counterface steel surface were analyzed by means of optical microscopy, scanning electron microscopy, and energy dispersive spectrometry. It is found that electroless plated Ag/MoS2 coating is able to greatly reduce the friction and wear of the EM textured steel disc coupled with GCr15 steel ring, mainly because of the formation of solid self-lubricating layer on the EM textured steel surface and of transferred lubricating film on counterface steel surface. The diameter and spacing of the dimples are suggested as 500 μm for acquiring the best wear resistance of the hard steel discs after electrochemical micromachining treatment and electroless plating of Ag/MoS2 solid lubricating coating.展开更多
Highly efficient Ag3PO4/MoS2 nanocomposite photocatalyst was synthe- sized using a wet chemical route with a low weight percentage of highly exfoliated MoS2 （0.1 wt.%） and monodispersed Ag3PO4 nanoparticles （-5.4 n...Highly efficient Ag3PO4/MoS2 nanocomposite photocatalyst was synthe- sized using a wet chemical route with a low weight percentage of highly exfoliated MoS2 （0.1 wt.%） and monodispersed Ag3PO4 nanoparticles （-5.4 nm）. The structural and optical properties of the nanocomposite were studied using various characterization techniques, such as XRD, TEM, Raman and absorption spectroscopy. The composite exhibits markedly enhanced photocatalytic activity with a low lamp power （60 W）. Using this composite, a high kinetic rate constant （k） value of 0.244 min^-1 was found. It was observed that -97.6% of dye degrade over the surface of nanocomposite catalyst within 15 min of illumination. The improved photocatalytic activity of Ag3PO4/MoS2 nanocomposite is attributed to the efficient interfacial charge separation, which was supported by the PL results. Large surface area of MoS2 nanosheets incorporated with well dispersed Ag3PO4 nanoparticles further increases charge separation, contributing to enhanced degradation efficiency. A possible mechanism for charge separation is also discussed.展开更多
基金supported by the the National NaturalScience Foundation of China(No.51205001)Foundation for Young Talents in College of Anhui Province(No.2012SQRL083ZD)the Talent Innovation Fund of An-hui Polytechnic University(No.S05305)
文摘The objective of this research is to prepare specially designed surface texture on hard steel surface by electrochemical micromachining (EM) and to incorporate electroless plated Ag/MoS2 solid lubricant coating into the dimples of EM textured steel surface to effectively reduce friction and wear of steel-steel contacts. The friction and wear behavior of the Ag/MoS2 solid lubricant coating on EM textured steel surface was evaluated in relation to the size and spacing of the dimples thereon. The microstructure of as-plated Ag/MoS2 solid lubricant coating and the morphology and elemental composition of the worn coating surface and counterface steel surface were analyzed by means of optical microscopy, scanning electron microscopy, and energy dispersive spectrometry. It is found that electroless plated Ag/MoS2 coating is able to greatly reduce the friction and wear of the EM textured steel disc coupled with GCr15 steel ring, mainly because of the formation of solid self-lubricating layer on the EM textured steel surface and of transferred lubricating film on counterface steel surface. The diameter and spacing of the dimples are suggested as 500 μm for acquiring the best wear resistance of the hard steel discs after electrochemical micromachining treatment and electroless plating of Ag/MoS2 solid lubricating coating.
文摘Highly efficient Ag3PO4/MoS2 nanocomposite photocatalyst was synthe- sized using a wet chemical route with a low weight percentage of highly exfoliated MoS2 （0.1 wt.%） and monodispersed Ag3PO4 nanoparticles （-5.4 nm）. The structural and optical properties of the nanocomposite were studied using various characterization techniques, such as XRD, TEM, Raman and absorption spectroscopy. The composite exhibits markedly enhanced photocatalytic activity with a low lamp power （60 W）. Using this composite, a high kinetic rate constant （k） value of 0.244 min^-1 was found. It was observed that -97.6% of dye degrade over the surface of nanocomposite catalyst within 15 min of illumination. The improved photocatalytic activity of Ag3PO4/MoS2 nanocomposite is attributed to the efficient interfacial charge separation, which was supported by the PL results. Large surface area of MoS2 nanosheets incorporated with well dispersed Ag3PO4 nanoparticles further increases charge separation, contributing to enhanced degradation efficiency. A possible mechanism for charge separation is also discussed.
