TY - JOUR

T1 - Phenomenological Rule from Correlations of Conduction/Valence Band Energies and Bandgap Energies in Semiconductor Photocatalysts

T2 - Calcium Bismuthates versus Strontium Bismuthates

AU - Shtarev, D. S.

AU - Ryabchuk, V. K.

AU - Rudakova, A. V.

AU - Shtareva, A. V.

AU - Molokeev, M. S.

AU - Kirichenko, E. A.

AU - Serpone, N.

PY - 2020/3/19

Y1 - 2020/3/19

N2 - A number of calcium bismuthates were synthesized (25 to 50 mol% in Ca) and characterized by XRD, SEM, EDX, XPS and DRS techniques; the latter provided an estimate of the bandgap energies (Ebg=2.41 to 3.29 eV) via Tauc plots for indirect transitions, whereas XPS established the potentials (vs NHE) of their respective valence bands (and thus the conduction bands). Linear correlations existed between EVB/ECB and Ebg that when compared with those of strontium bismuthates (reported earlier) showed that differences in energies at Ebg=0 eV are related to the difference in the absolute electronegativities of Ca and Sr, from which the following empirical phenomenological rule is postulated: replacing one alkaline earth metal in bismuthates by another causes the points of intersection of the linear correlations ECB(Ebg) and EVB(Ebg) to be displaced by an amount equal to twice the difference in absolute electronegativities of these metals.

AB - A number of calcium bismuthates were synthesized (25 to 50 mol% in Ca) and characterized by XRD, SEM, EDX, XPS and DRS techniques; the latter provided an estimate of the bandgap energies (Ebg=2.41 to 3.29 eV) via Tauc plots for indirect transitions, whereas XPS established the potentials (vs NHE) of their respective valence bands (and thus the conduction bands). Linear correlations existed between EVB/ECB and Ebg that when compared with those of strontium bismuthates (reported earlier) showed that differences in energies at Ebg=0 eV are related to the difference in the absolute electronegativities of Ca and Sr, from which the following empirical phenomenological rule is postulated: replacing one alkaline earth metal in bismuthates by another causes the points of intersection of the linear correlations ECB(Ebg) and EVB(Ebg) to be displaced by an amount equal to twice the difference in absolute electronegativities of these metals.

KW - bandgap energies

KW - calcium bismuthates

KW - linear correlation of E/E with E

KW - semiconductor photocatalysts

KW - strontium bismuthates

KW - E-VB with E-bg

KW - STRUCTURAL-PROPERTIES

KW - linear correlation of E-CB

UR - http://www.scopus.com/inward/record.url?scp=85078735598&partnerID=8YFLogxK

U2 - 10.1002/cctc.201902236

DO - 10.1002/cctc.201902236

M3 - Article

AN - SCOPUS:85078735598

VL - 12

SP - 1551

EP - 1555

JO - ChemCatChem

JF - ChemCatChem

SN - 1867-3880

IS - 6

ER -