Layered-type metal phosphates of BaNb2-xTaxP2O11(x=0,0.5,1.0,1.5,and 2.0)were synthesized us-ing a solid-state reaction method.The photophysical,optical,and photocatalytic hydrogen production properties of the resulting powders were investigated for the first time.Phase-pure and homogeneous powders with irregular morphologies were obtained at a calcination temperature of 1200℃.As the Ta content increased,the interlayer distance along the c-axis increased by up to 0.14％.Additionally,the op-tical bandgap values increased from 3.32 to 3.59 eV.The energy band positions were estimated from the Mott-Schottky measurements.BaNb2P2O11(x=0)exhibited the lowest conduction band edge position(-0.14 V vs.the normal hydrogen electrode,NHE),which is located above the water reduction potential(0.0 V vs.NHE).In comparison,BaTa2P2O11(x=2.0)exhibited the highest conduction band edge posi-tion(-0.29 V vs.NHE),comparable to that of TiO2.The photocatalytic activity for hydrogen produced from splitting water was measured under ultraviolet light irradiation.Notably,BaTa2P2O11 exhibited the highest activity(7.3 μmol/h),which was 15 and 10 times larger than BaNb2P2O11(0.5 μmol/h)and nano-TiO2(0.7 μmol/h),respectively.The activity of BaTa2P2O11increased to 24.4 μmol/h after deposition of the NiOx co-catalyst(1 wt.％),which remained stable during continuous operation(～35 h).

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

[1]Min Je Kang;Gill Sang Han;In Sun Cho-.Photophysical,optical,and photocatalytic hydrogen production properties of layered-type BaNb2-xTaxP2O11(x=0,0.5,1.0,1.5,and 2.0)compounds)[J].材料科学技术（英文版）,2022(03):26-32

BaNb2,xTaxP2O11,BaNb2P2O11,BaTa2P2O11,BaTa2P2O11increased

Photophysical,optical,photocatalytic,hydrogen,production,properties,layered,type,compounds,Layered,metal,phosphates,were,synthesized,solid,state,reaction,method,photophysical,resulting,powders,investigated,first,Phase,pure,homogeneous,irregular,morphologies,obtained,calcination,temperature,content,interlayer,distance,along,axis,by,up,Additionally,bandgap,values,from,eV,energy,positions,estimated,Mott,Schottky,measurements,exhibited,lowest,conduction,edge,normal,electrode,NHE,which,located,above,water,reduction,potential,In,comparison,highest,comparable,that,TiO2,activity,produced,splitting,was,measured,under,ultraviolet,light,irradiation,Notably,times,larger,than,nano,respectively,after,deposition,NiOx,catalyst,wt,remained,stable,during,continuous,operation

0.522878