Porous　nanocrystalline　Ln(2)Ti(2)O(7)　(In　=　Nd,　Gd,　Er)　was　prepared　by　a　facile　self-propagating　combustion　method　using　metal　nitrates　(Ln(NO3)(3)　(Ln　=　Nd,　Gd,　Er),　TiO(NO3)(2))　and　glydne.　The　photocatalytic　activity　of　Ln(2)Ti(2)O(7)　(In　=　Nd,　Gd,　Er)　was　evaluated　by　the　photocatalytic　degradation　of　methyl　orange　(MO).　The　results　showed　that　the　photocatalytic　activity　of　Ln(2)Ti(2)O(7)　(La　=　Gd,　Er)　with　cubic　pyrochlore　structure　was　higher　than　that　of　Nd2Ti2O7　with　monoclinic　perovskite　structure　and　Gd2Ti2O7　showed　the　best　photocatalytic　activity.　The　different　photocatalytic　activities　observed　for　Ln(2)Ti(2)O(7)　(La　=　Nd,　Gd,　Er)　could　be　related　to　its　different　crystal　structures　and　Ln　4f　shells.　(C)　2014　Published　by　Elsevier　B.V.