Table 1.

(Photo-)electrolysis performances.

System	#	Electrolyte	t (h)	Eapplied (V vs. RHE)	$j_{\mathrm{total},{\mathrm{TiO}}_2}$ (mA cm−2)	${\eta }_{{\mathrm{CO}}_2/\mathrm{CO}}$ (mV)	CO		H2
							FE [Select.] (%)	TONc	FE [Select.] (%)
EC	1	0.1 M KHCO3 CO2 sat. (pH = 6.8)	2	−0.51	1.22	400	63 [80]	1002	16 [20]
	2	0.1 M KH2PO4/K2HPO4 Ar sat. (pH = 6.8)	2	−0.51	3.00	NA	0 [0]	NA	86 [100]
PV–EC	3	0.1 M KHCO3 CO2 sat. (pH = 6.8)	2	0.14	0.90	−250	80 [80]	941	20 [20]
	4	0.1 M KHCO3 CO2 sat. (pH = 6.8)	2	−0.06	3.25	−50	96 [87]	4060	14 [13]
	5a	0.5 M KHCO3 CO2 sat. (pH = 7.2)	7	−0.03	1.78	−80	NR [82]	NR	NR [18]
PEC	6	0.1 M KHCO3 CO2 sat. (pH = 6.8)	2	−0.06	0.81	−50	89 [97]	8031	3 [3]
	7b	0.1 M KHCO3 CO2 sat. (pH = 6.8)	2	−0.06	0.05	−50	0 [0]	NA	31 [100]

^aUnder continuous gas flow.

^bNo catalyst.

^cLowest estimation (see Methods).

NA not applicable, NR not reported (experiments under gas flow).