Praise be to Allah.
What is well known among all the scholars, and is the opinion of the majority and almost reaches the point of consensus among the scholars of the righteous salaf, is that zakaah is not to be spent on building mosques or buying books etc., rather it is to be spent on the eight categories which are mentioned in the aayah of Soorat al-Tawbah [9:60], namely: the poor; the needy; those employed to collect the funds; those whose hearts are to be softened towards Islam; to release captives; for those who are in debt; for Allaah’s Cause (i.e., for the mujaahideen); and for wayfarers. The phrase fi sabeel Allaah (for Allaah’s Cause) refers exclusively to jihad. This is well known among the scholars, and this does not include spending zakaah on building mosques, schools, roads, etc. And Allaah is the Source of strength.