https://pureadmin.qub.ac.uk/ws/files/126683921/Edited_sudagar_R1.pdf

Electroless nickel, alloy, composite and nano coatings – A critical review

Decoupling natural resource use and environmental impacts from economic growth. A Report of the Working Group on Decoupling to the International Resource Panel / Fischer-Kowalski, M., Swilling, M., von Weizsacker, E.U., Ren, Y., Moriguchi, Y., Crane, W., Krausmann, F., Eisenmenger, N., Giljum, S., Hennicke, P., Romero Lankao, P., Siriban Manalang, A. UNEP, 2011, 174 p., ISBN: 978-92-807-3167-5 http://www.unep.org/resourcepanel/decoupling/files/pdf/Decoupling_Report_English.pdf Voir ci-dessous...

Decoupling natural resource use and environmental impacts from economic growth

Advanced Phosphorus-Based Materials for Lithium/Sodium-Ion Batteries: Recent Developments and Future Perspectives

A new processing concept has been developed to produce nano-structured metal-matrix composite coatings. This method combines sol-gel and electroless plating techniques to prepare highly dispersive oxide nano-particle reinforced composite coatings. Transparent TiO2 sol was added into the standard electroless plated Ni–P solution at a controlled rate to produce Ni–P–TiO2 nano-composite coatings on Mg alloys. The coating was found to have a crystalline structure. The nano-sized TiO2 particles (∼ 15 nm) were well dispersed into the Ni–P coating matrix during the co-deposition process. This technique can effectively avoid the agglomeration of nano-particles in the coating matrix. As a result, the microhardness of the composite coatings were significantly increased to ∼ 1025 HV200 compared to ∼ 710 HV200 of the conventional composite coatings produced with solid particle mixing methods. Correspondingly, the wear resistance of the new composite coatings was also greatly improved.

A novel electroless plating of Ni–P–TiO2 nano-composite coatings

Sodium-ion batteries (SIBs), a potential alternative to lithium ion batteries (LIBs), have attracted remarkable attention recently due to the natural abundance and low-cost of sodium. Here, we have presented a comprehensive study on combining electroless deposition with chemical dealloying to control the shell thickness and composition of a red phosphorus (RP)@Ni–P core@shell nanostructure as a high performance anode for SIBs. For the first time depending on regulating the dealloying time (1 h, 4 h, 8 h, 10 h and 20 h) of RP@Ni–P synthesized by electroless deposition of Ni on RP, 1 h RP@Ni–P, 4 h RP@Ni–P, 8 h RP@Ni–P, 10 h RP@Ni–P and 20 h RP@Ni–P with different shell thicknesses and compositions were prepared. The in situ generated Ni2P on RP particle surfaces can facilitate intimate contact between RP and a mechanically strong amorphous Ni–P outer shell with a high electronic conductivity, which ensures strong electrode structural integrity, a stable solid electrolyte interphase and ultra-fast electronic transport. As a result, the 8 h RP@Ni–P composite presents a super high capacity (1256.2 mA h gcomposite−1 after 200 cycles at 260 mA gcomposite−1), superior rate capability (491 mA h gcomposite−1 at 5200 mA gcomposite−1) and unprecedented ultralong cycle-life at 5000 mA gcomposite−1 for an RP-based SIB anode (409.1 mA h gcomposite−1 after 2000 cycles). This simple scalable synthesis approach will provide a new strategy for the optimization of core@shell nanostructures, paving the way for mass production of high performance electrodes for SIBs and other energy storage systems.

A controlled red phosphorus@Ni–P core@shell nanostructure as an ultralong cycle-life and superior high-rate anode for sodium-ion batteries

Composite coatings of modified amorphous nickel were prepared by simultaneous electroless deposition of NiP and TiO2 on brass, from a solution in which TiO2 particles were kept in suspension by stirring. Following short-term heat treatment in a high vacuum, the plating acquires chromium equivalent hardness. The deposit surfaces were studied by SEM, profilometry and Vickers microhardness and its structure by X-ray diffraction. The fabricated composite materials were tested under corrosion conditions by linear polarization measurements. The results show that after the heat treatment in a high vacuum for a very short time (10 min) the deposits acquire a crystalline microstructure, with very good adhesion to the substrate. In addition, the microhardness of vacuum heat-treated particle-free NiP coatings attained values of 1200 HV, while the composite NiP–TiO2 coatings acquired an even higher microhardness, exceeding 1450 HV. The corrosion resistance of the fabricated composite layers after heat treatment remained almost unaffected.

Electroless NiP–TiO2 composite coatings: Their production and properties

Vacuum heat treatment of electroless Ni–B coatings

Vacuum thermal treated electroless NiP-TiO2 composite coatings

Three different types of electroless nickel (EN)-phosphorus plating were applied on AZ31 wrought magnesium alloy. The first type was plain mid-phosphorus coating, the second one was duplex, with the first layer having a mid-phosphorus content and the upper one consisting of high-phosphorus whereas the third type of coating was also duplex with a first mid-phosphorus layer and a second high-phosphorus one with incorporated ceramic TiO 2 and ZrO 2 microparticles. Characterization of deposits by means of scanning electron microscopy and X-ray diffraction analysis proves the production of adherent, defect free coatings with differences in crystallinity depending on P content. Surface roughness was maintained at acceptable levels while a great increase in microhardness was observed that was further enhanced by ceramic microparticles incorporation. Electrochemical testing, that was performed by Tafel polarization in 3.5% NaCl solution, show that all the coatings effectively protect the Mg alloy substrate. Additionally, the composite coatings exceptionally enhance the protective capability of the system after heat treatment at 200 °C.

Characterization and corrosion resistance of duplex electroless Ni-P composite coatings on magnesium alloy

Lignocellulosic biomass is considered as a recalcitrant substrate for anaerobic digestion due to its complex nature that limits its biological degradation. Therefore, suitable preprocessing for the improvement of the performance of conventional anaerobic digestion remains a challenge in the development of anaerobic digestion technology. The physical and chemical characteristics of wheat straw (WS), as a representative lignocellulosic biomass, have a significant impact on the anaerobic digestion process in terms of quantity and quality of the produced biogas. This study aimed at investigating the enzymatic saccharification and detoxification of straw prior to anaerobic digestion with the final objective of enhancing the performance of conventional anaerobic systems of recalcitrant fractions of agricultural waste. The experimental activity was performed in lab and pilot scale treating WS. Alkaline delignification of straw using sodium hydroxide (NaOH) was studied prior to enzymatic hydrolysis for the production of easily biodegradable sugars. After defining the optimum conditions for the pretreatment scheme, the anaerobic digestability of the effluents produced was measured. Finally, the final liquid effluents were fed to a pilot scale anaerobic digester of 0.5 m3 volume, applying an increasing organic loading rate (OLR) regime (in terms of chemical oxygen demand (COD) from 0.2 to 15 kg COD/m3/day). The optimum conditions for the delignification and enzymatic hydrolysis of WS were defined as 0.5 M NaOH at 50 °C for 3–5 h and 15 μL Cellic CTec2/g pretreated straw at 50 °C. It was proven that the resulting liquid effluents could be fed to an anaerobic digester in the ratio that they are produced with satisfactory COD removal efficiencies (over 70%) for OLRs up to 10 kg COD/m3/day. This value is correspondent to a hydraulic retention time of around 7.5 days, much lower than the respective one for untreated straw (over 12 days).

J. Novakovic

Papers

Electroless NiP–TiO2 composite coatings: Their production and properties

Vacuum heat treatment of electroless Ni–B coatings

Vacuum thermal treated electroless NiP-TiO2 composite coatings

Characterization and corrosion resistance of duplex electroless Ni-P composite coatings on magnesium alloy

Towards upscaling the valorization of wheat straw residues: alkaline pretreatment using sodium hydroxide, enzymatic hydrolysis and biogas production