You will be shown an abstract from a materials science research paper. Your task is to extract all synthesis operations described in the abstract into a structured JSON format. Your output should be a JSON array. Each entry in the array should be a JSON object describing a single synthesis operation. This object should have the following fields:

- "trigger": A verbal predicate indicating a synthesis operation. This should be a string extracted directly from the abstract.
- "arguments": An array of arguments specifying aspects of the synthesis operation. Each entry in the array should be a length-2 array formatted as [<argument_text>, <argument_type>]. The `argument_text` should be a string extracted directly from the abstract. The `argument_type` should be one of the following types: ["Recipe_Precursor", "Atmospheric_Material", "Participant_Material", "Recipe_Target", "Solvent_Material"].

For instance, suppose an excerpt from the abstract reads:

Tetraethoxysilane (TEOS, 98%) and cetyltrimethylammonium bromide (CTAB, 98%) were purchased from Fluka. The MTTZ-siloxy derivative (triethoxysilyl-propyl-5-mercapto-1-methyl-tetrazole) was synthesized as previously described [38].

This excerpt includes two operations, which could be annotated as follows.

[{"arguments": [["Tetraethoxysilane", "Recipe_Precursor"], ["cetyltrimethylammonium bromide", "Recipe_Precursor"]], "trigger": "purchased"}, {"arguments": [["MTTZ-siloxy derivative", "Recipe_Target"]], "trigger": "synthesized"}]

In your response, please include the JSON and no other text.

Abstract:
10.1016/j.matlet.2017.01.142
Template synthesis of Zn2TiO4 and Zn2Ti3O8 nanorods by hydrothermal-calcination combined processes
0.200 mol Zn(NO3)2*6H2O and 0.015 mol La(NO3)3*6H2O were dissolved in 100 ml de-ionized water. NH4OH solution was slowly added until the pH was 10. Then 0.100 mol and 0.300 mol C4K2O9Ti*2H2O in 100 ml de-ionized water each were slowly added to the transparency solutions with keeping the pH at 10 throughout the process. These solutions were hydrothermally processed at 120 degC for 12 h. The samples were calcined at 750 degC for 5 h for further characterization.
[{"arguments": [["Zn(NO3)2*6H2O", "Recipe_Precursor"], ["water", "Solvent_Material"], ["La(NO3)3*6H2O", "Recipe_Precursor"]], "trigger": "dissolved"}, {"arguments": [["NH4OH", "Recipe_Precursor"]], "trigger": "added"}, {"arguments": [["C4K2O9Ti*2H2O", "Recipe_Precursor"], ["solutions", "Participant_Material"], ["water", "Solvent_Material"]], "trigger": "added"}, {"arguments": [["solutions", "Participant_Material"]], "trigger": "hydrothermally processed"}, {"arguments": [["samples", "Participant_Material"]], "trigger": "calcined"}]