Decoration of Carbon Nitride Surface with Bimetallic Nanoparticles (Ag/Pt, Ag/Pd, and Ag/Au) via Galvanic Exchange for Hydrogen Evolution Reaction

Abstract

Here, we propose the synthesis of AgPt, AgPd, and AgAu bimetallic nanoparticles (NPs) on a carbon nitride (C 3 N 4 ) surface via a galvanic exchange technique for the hydrogen evolution reaction (HER). Prior to the synthesis of C 3 N 4 / AgPt, AgPd, and AgAu, Ag NPs were synthesized on a C 3 N 4 surface. For the synthesis of Ag NPs, initially Ag + ions were adsorbed and then reduced by NaBH 4 resulting in the decoration of Ag NPs. These Ag NPs were then subjected to galvanic exchange where sacrificial Ag was replaced by Pt 2+ , Pd 2+ , and Au 3+ to fabricate AgPt, AgPd, and AgAu NPs. The galvanic exchange reaction occurs on a solid substrate, which favored slow exchange of Ag and resulted in the transformation of Ag into AgPt, AgPd, and AgAu alloys. The synthesized heterostructures were characterized with the help of PXRD, XPS, TEM, FESEM, and EDS techniques. All the materials were applied for hydrogen evolution using 0.5 M H 2 SO 4 solution. C 3 N 4 /AgPt shows efficient electrocatalytic activity as it requires only −150 mV potential to attain current density of 10 mA/cm 2 . Bimetallic catalysts synthesized through galvanic exchange proved very efficient as compared to monometallic C 3 N 4 /Ag.

AgPd Alloy Nanoparticles Decorated MoS2 2D Nanosheets: Efficient Hydrogen Evolution Catalyst in Wide pH Condition

“…Youn and co‐workers synthesized bimetallic nanoparticles (AuPd) using hydrazine on a graphite nitride surface for hydrogen evolution and oxygen evolution reaction and observed the superior activity of the alloy . Recently, our group also reported synthesis of Ag/Pt, Ag/Au and Ag/Pd alloy on C 3 N 4 surface for HER and observed that Ag/Pt is most active catalyst compared to others . Miao and co‐workers have shown Pt/Pd bimetallic nanoparticles on multiwall carbon nantotubes for better hydrogen evolution .…”

“…Therefore, all the synthesized materials can function as active catalyst in a wide range of pH. In our previous report, we observed that the AgPd alloy decorated on C 3 N 4 can generate current density of 10 mA/cm 2 upon application of −0.308 V vs. RHE where the substrate C 3 N 4 does not have any electrocatalytic activity in the observed potential window . In our present study, MoS 2 /AgPd‐2 can generate 10 mA/cm 2 current density in −0.215 V vs. RHE which signifies that the observed enhancement is the cumulative effect of both MoS 2 and AgPd alloy.…”

Development of Copper Cobalt Sulfide with Cu : Co Ratio Variation on Carbon Cloth as an Efficient Electrode Material for the Oxygen Evolution Reaction

“…[38][39][40] Figure 8a shows the plot of Tafel slopes of the synthesized materials. [41][42][43] R S and R CT values of RuO 2 /CC, Cu 2 CoS z /CC, CuCoS z / CC, CuCo 2 S z /CC, and CuCo 3 S z /CC are summarized in Table 2. It is clearly visible from Table 2 that CuCo 3 S z /CC electrocatalyst has the lowest Tafel slope value, which indicates better electrocatalytic activity in comparison with other electrocatalysts.…”

“…The data are fitted with the equivalent circuit that comprises of solution resistance (R S ), charge transfer resistance (R CT ), and constant phase element (CPE). [41][42][43] R S and R CT values of RuO 2 /CC, Cu 2 CoS z /CC, CuCoS z / CC, CuCo 2 S z /CC, and CuCo 3 S z /CC are summarized in Table 2. R CT value plays a vital role in controlling the electrocatalytic activity.…”

Tweaking Nickel with Minimal Silver in a Heterogeneous Alloy of Decahedral Geometry to Deliver Platinum‐like Hydrogen Evolution Activity

“…Figure c represents the amount of evolved hydrogen with time and dividing the experimental result by calculated value provides an extremely high efficiency of 99.4 %. The intrinsic figure of merit for HER electrocatalysts, the TOF of AgNi‐5 at 50 mV (versus RHE) is found to be 2.1 H 2 s −1 and at 150 mV (versus RHE) it is 14.6 H 2 s −1 (Supporting Information, Discussion S2), which is at par or larger than the best HER electrocatalysts reported till date (Supporting Information, Table S3) . AgNi‐5 NCs is also found to be remarkably stable both at pH 0 and pH 14 under operational conditions at −0.15 V overpotential for 5 days (Figure d), with no apparent change in its intertwined morphology (Figure d inset).…”