BaLa4Ti4O15 photocatalyst, one of the most active UV light responsive photocatalyst for water splitting, was modified with MgAl-LDH (layered double hydroxide) of an anion adsorbent to improve photocatalytic activity for reduction of nitrate to nitrogen. The activity of the Ni/BaLa4Ti4O15 photocatalyst was significantly improved by this surface modification with MgAl-LDH deposited by homogeneous precipitation using urea hydrolysis.