Yes. writing word in kanji or katakana sometimes works as emphasis. In other words, writing word in hiragana works as not to be emphasised.

Writing word in katakana that usually written in kanji is also works as emphasis with a bit different meaning. It tend to be used as stereotype. For example, 福島(Fukushima) / 広島(Hiroshima) is just a name of prefecture, but sometimes written フクシマ / ヒロシマ that refers nuclear plant accident / nuke bomb event. (I really dislike this usage).