Thermal decomposition technique

Figure 2. Co-nanocrystals synthesized using high-temperature thermal decomposition technique using thermal OA and TOPO as ligands.

Silver(I) /3-diketonate derivatives have received significant attention due to the ease with which they can be converted to the elemental metal by thermal decomposition techniques such as metal organic chemical vapor deposition (MOCVD).59 The larger cationic radius of silver(I) with respect to copper(I) has caused problems in achieving both good volatility and adequate stability of silver(I) complexes for the use in CVD apparatus. These problems have been overcome with the new techniques such as super critical fluid transport CVD (SFTCVD), aerosol-assisted CVD (AACVD), and spray pyrolysis, where the requirements for volatile precursors are less stringent. 

For technical purposes (as well as in the laboratory) RuOz and Ru based thin film electrodes are prepared by thermal decomposition techniques. Chlorides or other salts of the respective metals are dissolved in an aqueous or alcoholic solution, painted onto a valve metal substrate, dried and fired in the presence of air or oxygen. In order to achieve reasonable thicknesses the procedure has to be applied repetitively with a final firing for usually 1 hour at temperatures of around 450°C. A survey of the various processes can be found in Trasatti s book [44], For such thermal decomposition processes it is dangerous to assume that the bulk composition of the final sample is the same as the composition of the starting products. This is especially true for the surface composition. The knowledge of these parameters, however, is of vital importance for a better understanding of the electrochemical performance including stability of the electrode material. 

Hydrogen Analysis. The thermal decomposition technique was used to determine the hydrogen elemental composition. The sample was heated in vacuo to 925°C and was maintained at that temperature until all evolved gas was transferred by way of a Toepler pump to a calibrated gas buret. 

Nicolson [139] has described a rapid thermal decomposition technique for the atomic absorption determination of mercury in soils. In this method, air is used to sweep mercury vapour from the heated (650-750 °C) sample onto gold foil. In the second stage, heating of the gold foil releases mercury vapour into a cold vapour atomic absorption spectrometer. 

The aim of this work was to investigate the electrochemical behavior of Ir02 and Ru02 nanoparticles deposited on synthetic boron-doped diamond (BDD) surfaces by the thermal decomposition technique. 

Preparation bv the thermal decomposition technique (Ti/Ru02, Ti/Ir02)... 

Figure 3. Microphotograph of a Ti/Ir02 electrode prepared by the thermal decomposition technique.

Henri Bernard Beer developed and applied for two patents [20] issued in 1965 and 1967 that revolutionized the chlor-alkali industry. These patents described thermal decomposition techniques to coat titanium substrates with mixed crystals of valve metal... 

The kinetics of the OER were extensively examined [47-49] on various metal substrates and on metal oxides formed by thermal decomposition techniques. The polarization data for the OER on thermally formed metal oxides [50,51 ] in 4M KOH at 22°C are shown in Fig. 4.2.12. Generally, the Tafel slope is about 40mV for Ru02 in alkaline and acidic media, I1O2, and Pd02, but varies [27,32] from 30 mV on RUO2 to 120 mV on Pt02-... 

Using the thermal decomposition technique and analyzing the evolved gases, CO, CO2 and H2O with a quadrupole mass spectrometer, concentrations of total oxygen [O] (mmolg ) on the carbon surface could be assessed. 

Table 2.3. Comparison of some thermal decomposition techniques...

---