Supporting Information

Preparation, Optical and Photocatalytic studies of Defect Pyrochlores: KCr0.33W1.67O6 and AxCr0.33W1.67O6 nH2O

G.Ravia, Naveen Kumar Veldurthia, Muvva D.Prasadb, N.R.Muniratnamc, G.Prasadd and M.Vithala*

aDepartment of Chemistry, Osmania University, Hyderabad - 500 007, India

bSchool of Chemistry, University of Hyderabad, Hyderabad - 500 046, India

cCentre for Materials Electronics Technology(C-MET), IDA, Phase-III, Cherlapally, HCL post,

Hyderabad- 500 051, India

dDepartment of Physics, Osmania University, Hyderabad - 500 007, India

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*Corresponding author: E-mail address: (M. Vithal),

Tel: + 91 40-27682337, Fax: +91 40 27090020.

Figure S1 TGA curves of KCW and ion exchanged products of KCW

TableS1.The observed d – line values along with KSbWO6 d – lines

KSbWO6[1] / KCW / AgCW / SnCW / BiCW / SmCW / EuCW / GdCW
h k l / d (Å) / d (Å) / d (Å) / d (Å) / d (Å) / d (Å) / d (Å) / d (Å)
1 1 1 / 5.91 / 5.945 / 5.961 / 5.991 / 5.973 / 5.950 / 5.957 / 5.961
3 1 1 / 3.09 / 3.107 / 3.114 / 3.112 / 3.109 / 3.109 / 3.112 / 3.110
2 2 2 / 2.95 / 2.979 / 2.972 / 2.983 / 2.978 / 2.981 / 2.970 / 2.973
4 0 0 / 2.559 / 2.577 / 2.569 / 2.577 / 2.582 / 2.575 / 2.576 / 2.579
3 3 1 / 2.347 / 2.362 / 2.36 / 2.368 / 2.365 / 2.366 / 2.366 / 2.268
5 1 1 / 1.969 / 1.987 / 1.982 / 1.984 / 1.986 / 1.981 / 1.983 / 1.984
4 4 0 / 1.809 / 1.824 / 1.818 / 1.825 / 1.823 / 1.823 / 1.820 / 1.821
5 3 1 / 1.73 / 1.744 / 1.739 / 1.745 / 1.742 / 1.742 / 1.743 / 1.740
5 3 3 / 1.56 / 1.575 / 1.568 / 1.575 / 1.570 / 1.573 / 1.573 / 1.568
6 2 2 / 1.543 / 1.555 / 1.551 / 1.553 / 1.557 / 1.553 / 1.551 / 1.553
4 4 4 / 1.478 / 1.489 / 1.484 / 1.147 / 1.487 / 1.486 / 1.485 / 1.487
7 1 1 / 1.433 / 1.444 / 1.439 / 1.444 / 1.426 / 1.441 / 1.442 / 1.443
7 3 1 / 1.333 / 1.343 / 1.338 / 1.342 / 1.342 / 1.34 / 1.341 / 1.341
8 0 0 / 1.279 / 1.290 / 1.285 / 1.289 / 1.287 / 1.286 / 1.287 / 1.288

TableS2 The atomic positions, including fractional coordinates of the oxygens, occupancies and ‘R’ factors of KCW

Atom / Occupancy / Site / X / Y / Z
K / 0.25 / 32e / 0.445 / 0.445 / 0.445
Cr / 0.165 / 16c / 0 / 0 / 0
W / 0.835 / 16c / 0 / 0 / 0
O / 1.0 / 48f / 0.316 / 0.125 / 0.125

Rw(%)=20.65; Rwnb(%) = 18.84; Rb(%) = 16.05; Rexp(%) = 15.03; GOF (Goodness of fit) = 1.374

Table S3. The calculated d – line values of ion exchanged oxides

AgCW / SnCW / BiCW / SmCW / EuCW / GdCW
h k l / d (Å) / d (Å) / d (Å) / d (Å) / d (Å) / d (Å)
1 1 1 / 5.9405 / 5.9579 / 5.9527 / 5.9479 / 5.9479 / 5.9495
3 1 1 / 3.1023 / 3.1114 / 3.1087 / 3.1062 / 3.1062 / 3.1070
2 2 2 / 2.9702 / 2.9790 / 2.9764 / 2.9739 / 2.9740 / 2.9747
4 0 0 / 2.5723 / 2.5798 / 2.5776 / 2.5755 / 2.5755 / 2.5762
3 3 1 / 2.3604 / 2.3674 / 2.3654 / 2.3635 / 2.3635 / 2.3641
5 1 1 / 1.9802 / 1.9860 / 1.9842 / 1.9826 / 1.9826 / 1.9832
4 4 0 / 1.8189 / 1.8242 / 1.8226 / 1.8212 / 1.8212 / 1.8216
5 3 1 / 1.7392 / 1.7443 / 1.7428 / 1.7414 / 1.7414 / 1.7418
5 3 3 / 1.569 / 1.5737 / 1.5723 / 1.571 / 1.5711 / 1.5715
6 2 2 / 1.5511 / 1.5557 / 1.5544 / 1.5531 / 1.5531 / 1.5535
4 4 4 / 1.4851 / 1.4895 / 1.4882 / 1.487 / 1.487 / 1.4874
7 1 1 / 1.4408 / 1.445 / 1.4437 / 1.4426 / 1.4426 / 1.443
7 3 1 / 1.3395 / 1.3435 / 1.3423 / 1.3412 / 1.3412 / 1.3416
8 0 0 / 1.2862 / 1.2899 / 1.2888 / 1.2878 / 1.2878 / 1.2881

Figure S2. Energy dispersive spectra of (a) AgCW, (b) BiCW, (c) SmCW, (d) EuCW and (e)GdCW

Figure S3. (A) HRTEM image and (B) SAED patterns of AgCW

Figure S4. (A) HRTEM image and (B) SAED patterns of BiCW

Figure S5. (A) HRTEM image and (B) SAED patterns of SmCW

Figure S6. (A) HRTEM image and (B) SAED patterns of EuCW

Figure S7. (A) HRTEM image and (B) SAED patterns of GdCW

Table S4.IR band positions (cm-1) and their assignments of photocatalysts.ν and δ denote bending and stretching modes, respectively

KCW / SnCW / AgCW / BiCW / SmCW / EuCW / GdCW / Assignment
973 / 969 / 971 / 971 / 971 / 968 / 969 / ν (Cr/WO6)
784 / 809 / 821 / 790 / 829 / 832 / 821 / ν (Cr/WO6)
720 / 727 / 701 / 720 / 720 / 720 / 720 / ν (Cr/WO6)
663 / 668 / 668 / 668 / 668 / 669 / 669 / ν (Cr/WO6)
610 / 593 / 598 / 615 / 605 / 590 / 595 / ν (Cr/WO6)
450 / 456 / 454 / 456 / 456 / 457 / 457 / δ (Cr/WO6)
420 / 421 / 416 / 420 / 420 / 419 / 417 / δ (Cr/WO6)

Figure S8. Infrared spectra of KCW, AgCW, SnCW, BiCW, SmCW, EuCW and GdCW

Figure S9. UV-Visible absorption spectral changes of MB in the presence of SnCW

Figure S10. Fluorescence spectra of visible light irradiated SnCW suspensions in 3 mM terephthalic acid (λexcitation =320 nm)

Figure S11. Powder X-ray diffraction patterns of SnCW (a) before and (b) after MB degradtion