Transition metal nitride/sulfide nanoparticles attached to nitrogen-doped carbon nanotubes synthesized by modified black powder detonation for efficient overall water splitting

Abstract

To overcome the energy crisis, the rational construction of efficient electrolytic water catalysts is urgently required. Herein, an innovative proposal was presented for the preparation of self-supported electrolytic water catalysts on nickel foam (NF) substrates using modified black powder (BP) detonation method. The transient high temperature of the controlled detonation can obtain a variety of highly active catalytic components. First, carbon nanotubes (CNTs) were immobilized on NF by electroplating nickel to improve the pore utilization and electrical conductivity of NF. The unique hollow channel structure and extensive surface area of CNTs facilitated the attachment of the active catalysts. The introduction of Co metal salt not only controlled the reaction degreed effectively but also served as an effective transition metal source. With sulfur (S) source in BP and the additional nitrogen (N) source, the detonation successfully produced nano Co5.47N and Ni3S2. Nanocrystals Co5.47N and Ni3S2 along with N-doped CNTs, acquired via transient high-temperature reaction, were abound in defects. Consequently, the obtained sample exhibited excellent catalytic activities for both hydrogen evolution and oxygen evolution reactions. A remarkable overall water-splitting was achieved at a voltage of 1.52 V at 10 mA cm−2 in a two-electrode water electrolysis system.