Table 2.
A comparison of photocatalytic metal nanomaterials for antimicrobial applications
| Material | Shape | Size | Concentration | Irradiation | Micro‐organisms | Antimicrobial efficacy a) | Log reduction | Treatment parameters | Refs. |
|---|---|---|---|---|---|---|---|---|---|
| Bacteria | |||||||||
| TiO2 | Not specified | 79 nm | 100 ppm | 310 ≤ λ ≤ 400 nm | E. coli | 75% | NR | 13.6 W m−2, 6 h | [ 112 ] |
| Ni‐doped TiO2 | Sphere | 8–10 nm | 1 mg mL−1 Ni‐TiO2 in 5 mL saline water | λ > 400 nm |
S. aureus E. coli Salmonella albony B. subtilis |
>99% (4 h) >99% (5 h) >99% (6 h) >99% (4 h) |
4 3.5 3.3 4.3 |
≈0.5 mW cm−2, 0–6 h treatment |
[ 183 ] |
| Cu‐doped TiO2 | Sphere | 8–12 nm | 1 mg mL−1 Cu‐TiO2 in 5 mL saline water | λ > 400 nm |
S. aureus E. coli |
>99% (2 h) >99% (4 h) |
NR NR |
≈0.5 mW cm−2, 0–4 h treatment | [ 184 ] |
| Carbon‐doped TiO2 | Not specified | Not specified | 1 g L−1 |
λ > 385 nm λ > 455 nm |
E. coli |
>99% ≈80% |
NR NR |
1.8 W cm−2 (385 nm) 1.0 W cm−2 (455 nm), 2 h |
[ 204 ] |
| TiO2‐graphene | Sphere | 37 nm | 995 mg mL−1 | λ > 400 nm | E. coli | 64% | 0.443 |
450 W xenon lamp, ≈18 cm above sample, 440 min |
[ 185 ] |
| S‐doped TiO2 | Sphere | 10 nm | 0.2 mg mL−1 | λ > 420 nm | Micrococcus lylae | >95% | NR |
≈47 mW cm−2, 1 h |
[ 188 ] |
| Ag–TiO2 | Composites | 12.7–22.8 nm | 200 × 10−9 m | Visible light (not specified) | E. coli | >99% | NR |
Not specified 6 h |
[ 205 ] |
| CdS | Spheroids | 5–65 nm |
0.1 µg mL−1 0.5 µg mL−1 1 µg mL−1 |
λ > 420 nm |
E. coli S. aureus |
≈60 ≈80 >95% ≈55% ≈80% >90% |
NR |
300 W Xe lamp (does not specify distance from sample), 4 h |
[ 189 ] |
| ZnO | Not specified | Not specified | 0.01 mg mL−1 | 250 ≤ λ ≤ 400 nm |
E. coli P. aeruginosa S. aureus |
>99% (40 min) >99% (40 min) >99% (2 h) |
5 5 5 |
400 W sodium lamp ≈10 cm above sample, 0–4 h |
[ 195 ] |
| ZnO | Rods |
186 nm length 20 nm width |
1 g L−1 | 365 ≤ λ ≤ 750 nm | E. coli | ≈20% | 0.07 |
5.5 mW cm−2, 3 h |
[ 193 ] |
| n‐HA/ZnO | Rod |
80–90 nm length 15–30 nm diameter |
1 g mL−1 1 g mL−1 |
UV light (not specified) |
S. aureus E. coli |
99.45% 95.65% |
NR NR |
Not specified | [ 196 ] |
| nFe2O4–Ag–rGO | Particles and clusters bound to sheets | Not specified | 250 mg L−1 | λ > 400 nm | E. coli | >99% | 7.2 |
300 W Xe lamp (does not specify distance from sample), 90 min |
[ 197 ] |
|
Ag3PO4 GO‐AG3PO4 |
Rhombic Dodecahedral | 500 nm | 20 mg L−1 | 420 ≤ λ ≤ 630 nm | E. coli |
>99% >99% |
NR NR |
80 mW cm−2, 2 h |
[ 198 ] |
|
Au Ni Si Ag |
Spheres | 20–30 nm |
10 mg L−1 10 mg L−1 10 mg L−1 50 µg L−1 |
λ = 356 nm | E. coli |
≈10% ≈60% ≈80% ≈95% |
Check again |
0.78 mW cm−2, 2 h |
[ 114 ] |
| BiVO4 | Octahedral | 200–300 nm | 50 mg L−1 | Visible light (not specified) | E. coli | 88% | NR |
100 mW cm−2, 1 h |
[ 192 ] |
| CuO | Rods |
2.2 ± 0.67 µm length 70.1 ± 14.7 nm width |
5 ppm 10 ppm 20 ppm |
λ > 400 nm | E. coli |
pH 6.0 ≈40% ≈70% ≈92% pH 7.0 ≈30% ≈35% ≈45% |
NR |
pH 6.0 pH 7.0 15.6 mW cm−2, 2 h |
[ 199 ] |
| Fe‐doped CuO | Spheres | 21 nm | 100 µg mL−1 | Not specified |
S. aureus S. epidermidis |
≈20% ≈20% |
NR |
Not specified, 24 h |
[ 201 ] |
|
TiO2 |
Not specified | Not specified | 10 mg mL−1 | 315 ≤ λ ≤ 400 |
E. coli P. aeruginosa C. freundii S. aureus S. sapprophyticus |
>99% >99% >99% >99% >99% |
NR |
11 W, 20 min |
[ 200 ] |
|
ZnO |
Not specified | Not specified | 10 mg mL−1 | 315 ≤ λ ≤ 400 |
E. coli P. aeruginosa C. freundii S. aureus S. sapprophyticus |
>99% ≈97% ≈92% ≈90% ≈37% |
NR |
11 W, 20 min |
[ 200 ] |
| Fluorinated‐SnO2 | Hollow spheres |
100–200 nm (Cavity ≈50 nm) |
500 mg L−1 | λ > 365 nm | E. coli | >99% | 7.5 |
15 W, 150 min |
[ 191 ] |
| Ag–chitosan–TiO2 | Composites | ≈50 nm | 3.0 mg mL−1 | UV–vis (central wavelength 365 nm) |
E. coli S. aureus |
>99% >99% |
6 3.5 |
20 W, 2 h |
[ 206 ] |
| Fungi | |||||||||
| Ag–chitosan–TiO2 | Composites | ≈50 nm | 3.0 mg mL−1 | UV–vis (central wavelength 365 nm) | C. albicans | >99% | 4 |
20 W, 2 h |
[ 206 ] |
|
TiO2 |
Not specified | Not specified | 10 mg mL−1 | 315 ≤ λ ≤ 400 |
Aspergillus fumigatus Penicillum spp. |
>99% >99% |
NR |
11 W, 3 h |
[ 200 ] |
|
ZnO |
Not specified | Not specified | 10 mg mL−1 | 315 ≤ λ ≤ 400 |
Aspergillus fumigatus Penicillum spp. |
>99% >99% |
NR |
11 W, 3 h |
[ 200 ] |
| Carbon‐doped TiO2 | Not specified | Not specified | 1 g L−1 |
λ >385 nm λ > 455 nm |
C. albicans |
≈80% ≈20% |
NR |
1.8 W cm−2 (385 nm) 1.0 W cm−2 (455 nm), 2 h |
[ 204 ] |
| PdO‐modified N‐doped TiO2 | Nonuniform | 10–20 nm | 1 mg mL−1 | λ > 400 nm | Fusarium graminearum | >99% | 3.5 |
20 mW cm−2, 5 h |
[ 207 ] |
| TiO2 | Spheres | 30 nm | 0.1 g L−1 | λ > 340 nm |
Saccharomyces cerevisiae Botrytis cinerea Candida krusei Rhodotorula glutinis |
>99% <1% >99% ≈90% |
7 0 6.8 1 |
3.8 mW cm−2, 5 h |
[ 208 ] |
| Fe‐doped CuO | Spheres | 21 nm | 100 µg mL−1 | Not specified | C. albicans | ≈85% | NR |
Not specified, 24 h |
[ 201 ] |
| Au–methylene blue | Spheroids | 21 ± 2.5 nm | 20 µg mL−1 | λ = 660 nm | C. albicans | 82.2% | NR |
120 mW, 40 s |
[ 202 ] |
Antimicrobial efficacy may be due to combinatorial effects with other antimicrobial mechanisms in some cases. NR: Not reported.