TY - JOUR
T1 - Interstitial M+(M+= Li+or Sn4+) Doping at Interfacial BiVO4/WO3to Promote Photoelectrochemical Hydrogen Production
AU - Patil, Santosh S.
AU - Lee, Jaewon
AU - Park, Eunoak
AU - Nagappagari, Lakshmana Reddy
AU - Lee, Kiyoung
N1 - Publisher Copyright:
©
PY - 2021/12/27
Y1 - 2021/12/27
N2 - Doping metals together with heterostructure assemblages is critical to address the challenges encountered while using bismuth vanadate (BVO) to yield improved light-harvesting, charge transfer, and solar-to-hydrogen conversion efficiency. To date, most approaches have focused on substitutional doping using hexavalent metal ions (Mo6+ and W6+) at vanadium or bismuth sites to improve the photoelectrochemical (PEC) performance. Unlike conventional substitution, which produces V-substituted sites that function as hole traps and reduce the activity, herein, we used a simple hydrothermal and metal-organic decomposition approach to introduce interstitial [Li+ or Sn4+]n-doping in BVO (n = 0.25, 0.5, 1.0, 1.5, and 2.0 mM) interfaced with tungsten oxide (WO). The resulting Sn-doped BVO/WO (0.5 mM) shows a reproducible photocurrent density of 1.65 ± 0.07 mA cm-2 and 4.28 ± 0.15 mA cm-2 at 1.23 VRHE for water oxidation and sulfite oxidation, respectively, with a superior quantum efficiency (60% at 470 nm) and long-term durability (>10000 s) under standard AM 1.5 G light irradiation (1 sun). The results show that the Sn-doped BVO/WO exhibited an enhanced PEC performance approximately three times better than that of pristine BVO/WO, thus enabling continuous H2 production (∼800 μmol·cm-2) and highlighting the beneficial role of strategically controlled interstitial dopant concentration. Mott-Schottky analysis revealed an increase in the donor concentration for Li-BVO/WO (∼2.3-fold) and Sn-BVO/WO (3.5-fold), related to the reference BVO/WO photoelectrode. This work highlights the use of low-cost dopants and heterojunction photocatalysts to carry out hydrogen evolution reactions at a significantly improved rate.
AB - Doping metals together with heterostructure assemblages is critical to address the challenges encountered while using bismuth vanadate (BVO) to yield improved light-harvesting, charge transfer, and solar-to-hydrogen conversion efficiency. To date, most approaches have focused on substitutional doping using hexavalent metal ions (Mo6+ and W6+) at vanadium or bismuth sites to improve the photoelectrochemical (PEC) performance. Unlike conventional substitution, which produces V-substituted sites that function as hole traps and reduce the activity, herein, we used a simple hydrothermal and metal-organic decomposition approach to introduce interstitial [Li+ or Sn4+]n-doping in BVO (n = 0.25, 0.5, 1.0, 1.5, and 2.0 mM) interfaced with tungsten oxide (WO). The resulting Sn-doped BVO/WO (0.5 mM) shows a reproducible photocurrent density of 1.65 ± 0.07 mA cm-2 and 4.28 ± 0.15 mA cm-2 at 1.23 VRHE for water oxidation and sulfite oxidation, respectively, with a superior quantum efficiency (60% at 470 nm) and long-term durability (>10000 s) under standard AM 1.5 G light irradiation (1 sun). The results show that the Sn-doped BVO/WO exhibited an enhanced PEC performance approximately three times better than that of pristine BVO/WO, thus enabling continuous H2 production (∼800 μmol·cm-2) and highlighting the beneficial role of strategically controlled interstitial dopant concentration. Mott-Schottky analysis revealed an increase in the donor concentration for Li-BVO/WO (∼2.3-fold) and Sn-BVO/WO (3.5-fold), related to the reference BVO/WO photoelectrode. This work highlights the use of low-cost dopants and heterojunction photocatalysts to carry out hydrogen evolution reactions at a significantly improved rate.
KW - bismuth vanadate
KW - heterojunction
KW - hydrogen energy
KW - interstitial metal doping
KW - water splitting
UR - http://www.scopus.com/inward/record.url?scp=85120335335&partnerID=8YFLogxK
U2 - 10.1021/acsaem.1c02294
DO - 10.1021/acsaem.1c02294
M3 - Article
AN - SCOPUS:85120335335
SN - 2574-0962
VL - 4
SP - 13636
EP - 13645
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
IS - 12
ER -