“Research” is an uncountable noun; this means you cannot say:
“Many researches” or
“ Smith did a research”
You should write :
“A lot of research” or
“Smith did some research”
“Research” is a high-frequency word i.e. you are going to use it frequently in your academic writing.
[see High-frequency vocabulary]
For this reason, it is a good idea to use synonyms e.g. “investigation” or “studies”. These nouns are countable.
E.g. “ Many studies/investigations”
“Smith conducted some/several/numerous investigations/studies.”
You can therefore say “An investigation/study into….”
Although you can use the verb “to do” with research, there are better alternatives that sound more formal:
“ Jones et al. conducted research into the phenomenon of….”
“ Simpson (1999) carried out an investigation into….”