Can we use Kanji for 「もらう」(to receive)? If so, is it recommended?
You can. It's written 貰う in kanji. People will generally be able to read it.
It is, however, not recommended by the Agency for Cultural Affairs. The kanji 貰 and the reading もらう are not included on the Jōyō Kanji chart.
It is not recommended by the NHK漢字表記辞典 either. According to the NHK dictionary, this word should always be written in kana.
In any case, please make sure you write もらう in kana when using it as a subsidiary verb (補助動詞) as in 〜てもらう. Subsidiary verbs are generally written in kana.