I try to prepare Ws2 via hydrothermal route. I have tried many times by changing molar ratio, PH adjusting, added Hydroxlammine, Changing time & temperature. but the results are only a yellow coloured solution sometimes a little blue, but not even a single particles, its multiple failures in a row, still I didn't get my solution for this problem why its not forming? Hence I humbly request to help for further research studies
thanks in advance
I found cuprotungstite (in parts hydrated)in the Salamanca Cu mine Chile and ferritungstite hydrated at Ma Ta mae, Thae Doi Ngom and Pha Hao. Thailand. These are oxidation products which may have derived from tungstenite WS2.
The wolfram-disulfide seems to occur in nature at very low T under near ambient conditions see:
DILL, H.G., WEBER, B. and BOTZ, R. (2013) Metalliferous duricrusts (“orecretes”) - markers of weathering: A mineralogical and climatic-geomorphological approach to supergene Pb-Zn- Cu-Sb-P mineralization on different parent materials.- Neues Jahrbuch für Mineralogie Abhandlungen, 190: 123-195.
See also:
Ma Ta, Mae Thae, Doi Ngom, Pha Hao and Haii Nai deposits, Thailand: Vein-type Sb deposits with formation temperatures between 200 °C and 45 °C are hosted by Late Paleozoic calcareous rocks in the Lampang-Phrae Province in northern Thailand (Dill et al., 2008). After the diagenesis and dolomitization of calcareous rocks, mesothermal W mineralization with wolframite and scheelite, epithermal Sb-(As) mineralization with arsenopyrite, stibnite, fluorite, and marcasite and hot spring Sb deposition with pyrite and Fe–W–Sb oxides took place in the area (Table 1s). It was followed by hypogene and supergene alteration, resulting in the formation of Fe–Pb–Sb oxyhydroxides.
DILL, H.G. , MELCHER, F. and BOTZ, R. (2008) Meso- to epithermal W-bearing Sb vein-type deposits in calcareous rocks in western Thailand: with special reference to their metallogenetic position in SE Asia.- Ore Geology Reviews, 34: 242-262.
It also occurs at higher T in replacement deposits, similar to molybdenite (e.g. Cottonwood Canyon, USA, Mittersill, Austria) and in some pegmatites such as Přibyslavice near Čáslav, Czech Republic Čech et al. (1978 ), Němec ( 1973 , 1978 ),Povondra et al.( 1987 , 1998), Prachař et al. ( 1983 ).
I think these papers could help you;
They're available on the ResearchGate Server for download.
Dear G. Gautham Kumar many thanks for posting this interesting technical question on RG. There is a large body of chemical literature available in which the synthesis of materials like MoS2 and WS2 is described in detail. In the case that the hydrothermal method failed several times as described in your question, I think it might be a good idea to try a different synthetic method. For example, a simple precipitation method has been reported in the following article:
Large-scale surfactant-free synthesis of WS2 nanosheets: an investigation into the detailed reaction chemistry of colloidal precipitation and their application as an anode material for lithium-ion and sodium-ion batteries
Article Large-scale surfactant-free synthesis of WS2 nanosheets: an ...
The method described here is very easy and straightforward. A simple precipitation reaction between Na2WO4·2H2O and Na2S in water provides tingsten disulfide as a brown precipitate. After calcination at 850 °C under N2 black/grey WS2 powder is obtained.
Unfortunately this article has not been posted as public full text on RG. However, it is quite recent (published 2020) and three of the authors have RG profiles. Thus it should be very easy to request the full text directly from the corresponding author via RG.
Good luck with your research work and best wishes, Frank Edelmann
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