Table 1. Quantification of RuP3 and NiP on the NiO electrodes (determined by ICP-OES) and photocurrents (AM1.5G filter, 100 mW cm^–2 and λ > 400 nm) of the respective electrodes after 100 s CPPE at E_appl = 0.3 V vs. RHE at room temperature. RuP3 and NiP loading on ITO is also shown. Loading concentrations are reported for the geometrical surface area of the electrodes. ^a .

Composition	RuP3/nmol cm–2	NiP/nmol cm–2	|j|/μA cm–2(a)	|j|/μA cm–2(b)
NiO|RuP3	10.7 ± 0.3	—	0.51	3.0
NiO|RuP3–NiP	9.4 ± 1.6	3.57 ± 0.61(c)	0.94	n.d.(d)
NiO|RuP3–Zr4+	6.3 ± 2.2	—	0.76	7.62
NiO|RuP3–Zr4+–NiP	6.3 ± 3.1	4.98 ± 3.54(c)	6.40	14.0
NiO|RuP3–(Zr4+–NiP)2	n.d.	n.d.	8.82	n.d.
NiO|(RuP3–Zr4+)2–NiP	n.d.	n.d.	2.18	n.d.
ITO|RuP3–NiP	37.6 ± 0.2	14.3 ± 0.2	—	—
ITO|RuP3–Zr4+	53.2 ± 20.5	—	—	—
ITO|RuP3–Zr4+–NiP	41.3 ± 20.3	19.2 ± 9.9	—	—

^aMeasured in ^(a)the absence and ^(b)presence of DTDP as SEA. ^(c)Calculated value from RuP3 : NiP ratio on ITO. ^(d)Not determined.