Department of Materials Science and Engineering;
Ajou University;
Suwon 16499;
Republic of Korea;
Department of Energy Systems Research;
Ajou University;
Suwon 16499;
Republic of Korea;
School of Advanced Materials Science and Engineering;
Sungkyunkwan University;
Suwon 16419;
Republic of Korea;
BaNb_(2)P_(2)O_(11); BaTa_(2)P_(2)O_(11); Layered crystal structure; Bandgap; Band edge positions; Photocatalytic hydrogen production;