Great efforts have been paid to enhance the photoelectrochemical performances of LaFeO.sub.3. However, there have rarely been reported about modifying of LaFeO.sub.3 with transitional metal borides for enhanced photoelectrochemical activities. Herein, we prepared LFO/Ni-B composite electrodes by immersing LFO into the prepared electroless plating solution. The optimized LFO/Ni-B composite exhibits a 373% improvement of the photocurrent density and exhibits an anodic shift of onset potential. Systematic studies reveal that the improvement of PEC activity should be attributed to enhanced electrochemically active surface area and electrocatalytic properties, reduced resistance of the PEC system, and a more pronounced downward band bending at the photoelectrode/electrolyte interface.