h-BN/ZnO　composite　photocatalysts　were　prepared　by　ball　milling　of　ZnO　with　hexagonal　BN　(h-BN).　The　photocatalytic　activity　of　ZnO　for　the　degradation　of　cationic　dyes　could　be　significantly　enhanced　by　coupling　with　ball　milled　h-BN　and　the　stability　of　ZnO　benefited　from　the　presence　of　h-BN　as　well.　However,　for　the　degradation　of　anionic　dyes,　no　apparent　enhancement　was　observed.　The　optimal　amount　of　h-BN　and　the　ball　milling　time　were　found　to　be　1.0　wt.%　and　20　min,　respectively.　Through　various　characterization　techniques　(XRD,　UV-vis　DRS,　SEM,　TEM,　and　terephthalic　acid　photoluminescence　probing)　and　the　compared　photocatalytic　degradation　experiments,　the　observed　photocatalytic　behaviors　could　be　attributed　to　the　negatively　charged　h-BN　created　by　the　ball　milling　process.　The　role　of　the　milled　h-BN　was　discussed　to　serve　as　(1)　holes-transfer　promoter　and　(2)　attractive　or　repulsive　sites　for　the　adsorption　of　the　charged　dyes　via　electrostatic　forces.　The　study　confirms　that　the　ball　milled　h-BN　could　be　used　as　a　holes　transfer　promoter　for　ZnO.　However,　the　finial　photocatalytic　performance　of　h-BN/ZnO　is　determined　by　the　superposition　of　the　two　effects　for　a　specific　degradation　process.　This　is　the　reason　why　the　enhancement　of　ball　milled　h-BN　is　only　effective　for　cationic　dyes.　(C)　2013　Elsevier　B.V.　All　rights　reserved.