UV irradiation onto a non-aqueous suspension of semiconductor–zeolite composite catalysts with N-(β-hydroxypropyl)ethylenediamine (N-β-HPEDA) produces 2-methylpiperazine and piperazine. The yield of 2-methylpiperazine and piperazine depends on the type of semiconductor and zeolite. A 5 wt% TiO₂–Hβ composite photocatalyst shows highest yield of 2-methylpiperazine.