What you've written means that two people are holding one box. Is that what you wanted? If not then it should be "... holding donation boxes ..."
"people" is usually better than "persons", and so it is here.
"donating box" sounds odd to me. You should say "donation box".
"holding ... on their hands" is almost always wrong, and is here.
"holding ... with their hands" is possible but not very natural.
"holding .. in their hands" is most natural.
However, you don't really need any of these: "... holding a donation box." is fine by itself. The "hands" part doesn't really add any value (how else would they be holding it?)