Table 5. Comparison of photocatalytic performance of Nb:W co-doped SnO₂ electrodes vs. that of other TCO-based photoelectrodes.

Sl. No.	Photoelectrode – parameters	aDye for degradation	Pollutant volume/catalyst area/light source	Performance highlights (resources)
1	TiO2 – varying calcination temperature	Degradation of MO	25 ml/80 cm2/15 W UV lamp	TiO2 film calcined at 700 °C showed the highest rate constant of 0.0018 min−1 (ref. 8)
2	TiO2 – Sn ion implantation	Degradation of Rh B	5 ml/5 cm2/8 W UV lamp	Rh B was degraded up to 80% after 160 min (ref. 9)
3	TiO2 – thickness variation	Degradation of SA	100 μL/4 cm2/UV-A lamp	TiO2 film of thickness 190 nm showed the highest activity with a rate constant 0.01648 min−1 (ref. 10)
4	Al/TiO2 – thermal deposition of the Al layer	Rh B	1.5 cm2/sunlight	An abatement of 30% was obtained for the degradation of Rh B11
5	TiO2–ZnO – Ag doping	Degradation of MB	2 ml/1 cm2/15 W UV lamp	2 mol% Ag-doped TiO2 – ZnO films showed an efficiency of 80% with a rate constant of 0.758 h−1 (ref. 12)
6	ZnO – Cu doping	Degradation of orange II	Visible light	Pure ZnO film showed 72% degradation efficiency and it decreased with increasing Cu doping13
7	ZnO – multilayer film (ZnO/AZO/ZnO) with Al doping	Degradation of MB	40 ml/24 cm2/750 W	Maximum efficiency of 95.2% with a rate of 1.02 h−1 was obtained at 20% Al doping14
8	ZnO – Al doping	Degradation of MB	50 ml/1 cm2/15 W UV lamp	Al doped ZnO films showed an efficiency of 80% with a rate constant of 0.002 min−1 (ref. 15)
9	ZnO – Co doping	Degradation of MB	50 ml/1 cm2/100 W	15 wt% Co doped ZnO film showed 100% degradation with a rate constant of 0.013 min−1 (ref. 16)
10	SnO2 – Fe, Ni doping	Degradation of MB	15 ml/11 W UV lamp	∼85% efficiency was obtained for the Fe and Ni doped SnO2 with a rate constant of 0.004 min−1 (ref. 17)
11	ZnO and SnO2 – substrate modification (polytherimide and glass)	Degradation of CV	50 ml/2 cm2/100 W UV lamp	ZnO and SnO2 films (with a polytherimide substrate) showed an efficiency of 80 and 85% with a rate constant of 0.009 and 0.006 min−1 (ref. 18)
12	SnO2 – F doping	Degradation of CV	50 ml/2 cm2/100 W UV-lamp	Degradation efficiency increases to 96% and 92% for pure and F: SnO2 on adding H2O2 respectively19
13	SnO2 – Ce doping	Degradation of MB	20 ml/3.75 cm2/UV lamp	Degradation of 19.10% is obtained for 2 wt% Ce:SnO2 (ref. 20)
14	SnO2 – Sr doping	Degradation of MB	20 ml/15 W UV lamp	Degradation efficiency of 38% was achieved for an 8 wt% Sr doped SnO2 film with a rate constant of 0.005 min−1 (ref. 21)
15	SnO2 – Nb, W doping	Degradation of (MV + MG + MB) MD	6 ml/4 cm2/200 W LED light	Significant degradation efficiency (73%:methyl violet, 79.1%:malachite green, and 83%:methylene blue) is achieved within 120 min (present work)

^aMethylene Blue – MB, Rhodamine B – Rh B, Methyl Orange – MO, Stearic Acid – SA, and Crystal Violet – CV.