作为谢意 in acknowledgment of

作为答谢 in return

为感谢 thank sb for sth

为了感谢你的帮助 Thanks for your help

作为答谢/回报/交换 in return

为某事感谢 thank you for

为某事感谢某人 thank sb for sth ; thanks for doing sth ; Thank Sb. for Sth./doing Sth

为酬谢 in recognition of

为某事而酬谢某人 reward sb. for sth./doing sth ; give/offer a reward to sb. for sth