No, except for very few situations, the word
解决 cannot be substituted for each other.
(Very few cases are considered to enlarge the usage informally. Since, in a sense, 'solving' a question certainly includes 'clarifying' a question, everything does have the potential possibility to be 'solved'
But semantically, they have distinct differences. The word
澄清 emphasizes through statements or explanations, the unknown truth or misunderstanding was clear, just like people usually say, 'are we clear?', 'we clear'. Until now, we hadn't moved to do anything, nor was there something we needed to do.
On the other hand, people use the word
解决 in the circumstances like 'conquering the difficulty', 'solving trouble', etc., which emphasizes exerting strength, efforts or methods and getting good results.